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PRINCIPLES

GEOLOGY

VOL IV.

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London :
Printed by a. Spottiswoode,

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PRINCIPLES

GEOLOGY:

BEING

AN INQUIRY HOW FAR THE FORMER CHANGES OF

THE EARTH'S SURFACE

REFERABLE TO CAUSES NOW IN OPERATION.

CHARLES LYELL, Esq. F.R.S.

PRESIDENT OF THE GEOLOGICAL SOCIETY OF LONDON

" The stony rocks are not primeval, but the daughters of Time."

LiNNiEus, Syst. Nat., Ed. 5. Stockholm, 1748, p. 219

IN FOUR VOLUMES.

VOL. IV.

THE FIFTH EDITION.

LONDON:

JOHN MURRAY, ALBEMARLE STREET

1837.

: » v

■ v' -

PRINCIPLES OF GEOLOGY.

BOOK IV.

CHAPTER X

NEWER PLIOCENE FORMATIONS

MARINE AND VOLCANIC

Tertiary formations of Campania — Comparison of the recorded
changes in this region with those commemorated by geological
monuments — Dikes of Somma — Parallelism of their opposite
sides (p. 6.)— Age of the volcanic and associated rocks of
Campania — Organic remains — No signs of diluvial waves
Marine Newer Pliocene strata chiefly seen in countries of earth-
quakes (p. 16.) — Illustrations from Chili — Peru — Paralle
roads of Coquimbo — West Indies (p. 21.) — East Indian
archipelago — Red Sea.

Tertiary Formations of Campania.

C omparison of recorded changes with those commemo-
rated by geological monuments. — In the second volume
I traced the various changes which the volcanic region
of Naples is known to have undergone during the last
two thousand years ; and, imperfect as are our histori-
cal records, the aggregate effect of igneous and aqueous
agency, during that period, was shown to be far from
insignificant. The rise of the modern cone of Vesu-
vius, since the year 79, was the most memorable event

VOL. IV.

NEWER PLIOCENE PERIOD.

[Book IV.

during those twenty centuries ; but, in addition to this
remarkable phenomenon, I enumerated the production
of several new minor cones in Ischia, and of the Monte
Nuovo, in the year 1538. The flowing also of lava
currents upon the land and along the bottom of the
sea was described, — the showering down of volcanic
sand, pumice, and scoriae, in such abundance that whole
cities were buried, — the filling up or shoaling of
certain tracts of the sea, and the transportation of
tufaceous sediment by rivers and land floods. I also
explained the evidence in proof of a permanent alter-
ation of the relative levels of the land and sea in
several places, and of the same tract having, near
Puzzuoli, been alternately upheaved and depressed to
the amount of more than twenty feet. In connection
with these convulsions, I pointed oat that, on the
shores of the Bay of Baiae, there are recent tufaceous
strata filled with fabricated articles, mingled with
marine shells. It was also shown that the sea has
been making gradual advances upon the coast, not only
sweeping away the soft tuffs of the Bay of Baiae, but
excavating precipitous cliffs, where the hard Ischian
and Vesuvian lavas have flowed down into the deep.
These events, it maybe objected, although interest-
are the results of operations on a very inferior
scale to those indicated by geological monuments.
When we examine this same region, it will be said we
find that the ancient cone of Vesuvius, called Somma,
is larger than the modern cone, and is intersected by
a greater number of dikes, — the hills of unknown
antiquity, such as Astroni, the Solfatara, and Monte
Barbaro, formed by separate eruptions, in different
parts of the Phlegraean fields, far outnumber those of

ing

Ch. X.]

TERTIARY FORMATIONS OF CAMPANIA

similar origin, which are recorded to have been thrown
up within the historical era. In place of modern tuffs
of slight thickness, and single flows of lava, we find,
amongst the older formations, hills from 500 to more
than 2000 feet in height, composed of an immense
series of tufaceous strata, alternating with distinct lava
currents. We have evidence that, in the lapse of past
ages, districts, not merely a few miles square, were up-
raised to the height of twenty or thirty feet above their
former level, but that extensive and mountainous coun-
tries were uplifted to an elevation of more than 1000
feet, and at some points more than 2000 feet, above
the level of the sea.

These and similar objections are made by those who
compare the modern effects of igneous and aqueous
causes, not with a part but with the whole results of
the same agency in antecedent ages. Thus viewed in
the aggregate, the leading geological features of each
district must always appear to be on a colossal scale,
just as a large edifice may seem an effort of super-
human power, until we reflect on the innumerable
minute parts of which it is composed, the number of
the builders, and the time required to raise it. A
mountain mass, so long as the imagination is occupied
in contemplating the gigantic whole, must appear the
work of extraordinary causes ; but when the separate
portions of which it is made up are carefully studied,
they are seen to have been formed successively ; and
the dimensions of each part, considered singly, are
soon recognized to be comparatively insignificant, so
that it appears no longer extravagant to liken them to
the recorded effects of ordinary causes.

■

B 2

NEWER PLIOCENE PERIOD

[Book IV

Difference in the composition of Somma and Vesuvius.

As no traditional accounts have been handed down
to us of the eruptions of the ancient Vesuvius, from
the times of the earliest Greek colonists, the volcano
must have been dormant for many centuries, perhaps
for thousands of years, previous to the great eruption
in the reign of Titus. But it will be shown hereafter
that there are sufficient grounds for presuming this
mountain, and the other igneous products of Cam-
pania, to have been produced during the Newer Plio-
cene period.

We have seen that the ancient and modern cones

of Vesuvius were each a counterpart of the other in

structure * ; and I may now remark that the principal

point of difference consists in the greater abundance

in the older cone of fragments of altered sedimentary

rocks ejected during eruptions.

ceive that the first explosions would act with the

greatest violence, rending and shattering whatever

solid masses obstructed the escape of lava and the

accompanying gases, so that great heaps of ejected

pieces of rock would naturally occur in the tufaceous

breccias formed by the earliest eruptions. But when

a passage had once been opened and an habitual vent

established, the materials thrown out would consist of

liquid lava, which would take the form of sand and

or of angular fragments of such solid lavas as

may have choked up the vent.

Among the fragments which abound in the tuface-
ous breccias of Somma, none are more common than
a saccharoid dolomite, supposed to have been derived

scorise

* Vol. II, p. 87

fcfc. X.]

DIKES OF SOMMA.

from an ordinary limestone altered by heat and vol-
canic vapours.

Carbonate of lime enters into the composition o*
so many of the simple minerals found in Somma, that
M. Mitscherlich, with much probability, ascribes their
great variety to the action of the volcanic heat on
subjacent masses of limestone.

Dikes of

The dikes seen in the great es-

carpment which Somma presents towards the modern
cone of Vesuvius are very numerous. They are for
the most part vertical, and traverse at right angles the
beds of lava, scoriae, volcanic breccia, and sand, o.
which the ancient cone is composed. They project in
relief several inches, or sometimes feet, from the face
of the cliff, like the dikes of Etna already described
(see Fig. 102.), being, like them, extremely compact,
and less destructible than the intersected tuffs and
porous lavas. In vertical extent they vary from a few
yards to 500 feet, and in breadth from one to twelve
feet. Many of them cut all the inclined beds in the
escarpment of Somma from top to bottom, others stop
short before they ascend above half way, and a few
terminate at both ends, either in a point or abruptly.
In mineral composition they scarcely differ from the
lavas of Somma, the rock consisting of a base of leucite
and augite, through which large crystals of augite and
some of leucite are scattered.* Examples are not
rare of one dike cutting through another, and in one
instance a shift or fault is seen at the point of intersec-
tion. I observed before, when speaking of the dikes
of the modern cone of Vesuvius, that they must have

* Consult the valuable memoir of M. L. A. Necker, M£m. de
la Soc. de Phys. et d'Hist. Nat. de Geneve, tome ii. parti., Nov.

1822.

B 3

NEWER PLIOCENE PERIOD.

[Book IV.

been produced by the filling up of open fissures by
liquid lava.* In some examples, however, the rents
seem to have been filled laterally.

The reader will remember the description before
given of the manner in which the plain of Jerocarne,
in Calabria, was fissured by the earthquake of 1783,
so that the academicians compared it to the cracks in
a broken pane of glass, f If we suppose the side
walls of the ancient crater of Vesuvius to have been

Fig. 109.

Bikes or veins at the Punto del Nasone on Somma.

cracked in like manner, and the lava to have entered
the rents and become consolidated, we can explain the
singular form of the veins figured in the accompanying

■t

of their

Nothing is more

remarkable than the parallelism of the opposite sides
of the dikes, which usually correspond with as much

Vol. II. p. 86.

f See Vol. II. p. 223. Fig. 47.

| From a drawing of M. Necker, in Mem. before cited

€h. X.]

PARALLEL SIDES OF DIKES.

regularity as the two opposite faces of a wall of ma-

■

sonry. This character appears at first the more inex-
plicable, when we consider how jagged and uneven
are the rents caused by earthquakes in masses of
heterogeneous composition like those composing the
cone of Somma ; but M. Necker has offered an in-
genious and, I think, satisfactory explanation of the
phenomenon. He refers us to Sir W. Hamilton's
account of an eruption of Vesuvius in the year 1 779,
who records the following facts : — * The lavas, when
they either boiled over the crater, or broke out from
the conical parts of the volcano, constantly formed
channels as regular as if they had been cut by art,
down the steep part of the mountain ; and, whilst in
a state of perfect fusion, continued their course in
those channels, which were sometimes full to the brim,
and at other times more or less so, according to the
quantity of matter in motion.

" These channels, upon examination after an erup-
tion, I have found to be in general from two to five or
six feet wide, and seven or eight feet deep. They
were often hid from the sight by a quantity of scoriae
that had formed a crust over them ; and the lava,
having been conveyed in a covered way for some

yards, came out fresh again into an open channel.

After an eruption I have walked in some of those sub-
terraneous or covered galleries, which were exceed-
ingly curious, the sides, top, and bottom being worn
"perfectly smooth and even in most parts, by the violence
of the currents of the red-hot lavas, which they had
^conveyed for many weeks successively."

In another place, in the same memoir, he describes
the liquid and red-hot matter as being received " into
& regular channel, raised upon a sort of wall of scoriae

b 4

NEWER PLIOCENE PERIOD.

[Book IV.

and cinders, almost perpendicularly, of about the
height of eight or ten feet, resembling much an ancient
aqueduct."*

Now, if the lava in these instances had not run out
from the covered channel, in consequence of the de-
clivity whereon it was placed —if, instead of the space
being left empty, the lava had been retained within
until it cooled and consolidated, it would then have
constituted a small dike with parallel sides. But the
walls of a vertical fissure through which lava has as-
cended in its way to a volcanic vent, must have been
exposed to the same erosion as the four sides of the
channels before adverted to. The prolonged and uni-
form friction of the heavy fluid, as it is forced and
made to flow upwards, cannot fail to wear and smooth
down the surfaces on which it rubs, and the intense
heat must melt all such masses as project and obstruct
the passage of the incandescent fluid.

I do not mean to assert that the sides of fissures
caused by earthquakes are never smooth and parallel,
but they are usually uneven, and are often seen to
have been so where volcanic or trap dikes are as regu-
lar in shape as those of Somma. The solution, there-
fore, of this problem, in reference to the modern dikes,
is most interesting, as being of very general applica-
tion in geology.

Varieties in their texture.

Having explained the

origin of the parallelism of the sides of a dike, we have
next to consider the difference of its texture at the
edges and in the middle. Towards the centre, observes
M. Necker, the rock is larger grained, the component
elements being in a far more crystalline state ; while at

* Phil. Trans., vol. lxx. 1780,

ft +^^m

Ch. X.]

VARIETIES IN THE TEXTURE OF DIKES.

the edge the lava is sometimes vitreous, and always
finer grained. A thin parting band, approaching in its
character to pitchstone, occasionally intervenes on the
contact of the vertical dike and intersected beds. M.
Necker mentions one of these at the place called
Primo Monte, in the Atrio del Cavallo ; I saw three
or four others in different parts of the great escarp-
ment. These phenomena are in perfect harmony with
the results of the experiments of Sir James Hall and
Mr. Gregory Watt, which have shown that a glassy
texture is the effect of sudden cooling, and that, on
the contrary, a crystalline grain is produced where
fused minerals are allowed to consolidate slowly and
tranquilly under high pressure.

It is evident that the central portion of the lava in
a fissure would, during consolidation, part with its heat
more slowly than the sides, although the contrast of
circumstances would not be so great as when we com-
pare the lava at the bottom and at the surface of a
current flowing in the open air. In this case the up-
permost part, where it has been in contact with the
atmosphere, and where refrigeration has been most
rapid, is always found to consist of scoriform, vitreous,
and porous lava, while at a greater depth the mass
assumes a more lithoidal structure, and then becomes
more and more stony as we descend, until at length
we are able to recognize with a magnifying glass the
simple minerals of which the rock is composed. On
penetrating still deeper, we can detect the constituent
parts by the naked eye, and in the Vesuvian currents
distinct crystals of augite and leucite become ap-
parent.

The same phenomenon, observes M. Necker, may
readily be exhibited on a smaller scale, if we detach

b 5

►

r 1

NEWER PLIOCENE PEKIOD.

[Book IV

a piece of liquid lava from a moving current. The
fragment cools instantly, and we find the surface
covered with a vitreous coat, while the interior, al-
though extremely fine grained, has a more stony
appearance.

It must, however, be observed, that although the
lateral portions of the dikes are finer grained than the
central, yet the vitreous parting layer before alluded to
is extremely rare. This may, perhaps, be accounted
for, as the above-mentioned author suggests, by the
great heat which the walls of a fissure may acquire
before the fluid mass begins to consolidate, in which
case the lava, even at the sides, would cool very
slowly. Some fissures, also, may be filled from above ;
and in this case the refrigeration at the sides would
be more rapid than when the melted matter flowed
upwards from the volcanic foci, in an intensely heated

state.

The rock composing the dikes of Somma is far more

compact than that of ordinary lava, for the pressure of

a column of melted matter in a fissure greatly exceeds

that in an ordinary stream of lava ; and pressure checks

the expansion of those gases which give rise to vesicles

in lava.

There is a tendency in almost all the Vesuvian dikes
to divide into horizontal prisms*, a phenomenon in
accordance with the formation of vertical columns in
horizontal beds of lava ; for in both cases the divisions
which give rise to the prismatic structure are at right

angles to the cooling surfaces.
Minor cones of

In the vol-

canic

* See Fig. 109. p. 6

(

Ch. X.]

MINOR CONES OF CAMPANIA.

conical hills with craters on their summits, which have
evidently been produced by one or more explosions,
like that which threw up the Monte Nuovo in 1538.
They are composed of trachytic tuff, which is loose
and incoherent, both in the hills and, to a certain
depth, in the plains around their base, but which is in-
durated below. It is suggested by Mr. Scrope, that
this difference may be owing to the circumstance of
the volcanic vents having burst out in a shallow sea,
as was the case with Monte Nuovo, where there is a
similar foundation of hard tuff, under a covering of
loose lapilli. The subaqueous part may have become
solid by an aggregative process like that which takes
place in the setting of mortar, while the rest of the
ejections, having accumulated on dry land when the
cone was raised above the water, may have remained
in a loose state.*

Age of the volcanic and associated rocks of Campania.

If we inquire into the evidence derivable from or-
ganic remains, respecting the age of the volcanic rocks
of Campania, we find reason to conclude that such
parts as do not belong to the Recent are referable to
the Newer Pliocene period. In the solid tuff quarried
out of the hills immediately behind Naples, are found
recent shells of the genera Ostrea, Cardium, Buccinum,
and Patella, all referable to species now living in the
Mediterranean. f In the centre of Ischia the lofty
hill called Epomeo, or San Nicola, is composed of
greenish indurated tuff of a prodigious thickness, inter-
stratified in some parts with argillaceous marl, and
here and there with great streams of indurated lava.
Visconti ascertained by trigonometrical measurement

Geo]. Trans., vol. ii. partiii. p. 351. Second Series,
t Scrope, ibid.

B 6

¥ ,

NEWER PLIOCENE PERIOD.

[Book IV.

that this mountain was 2605 feet above the level of
the sea. In mineral composition and in form, as seen
from many points of view, it resembles the hill to the
north of Naples on the summit of which stands the
convent of Camaldoli, which is 1643 feet in height. I
collected in 1828 many recent marine shells from beds

■

of clay and tuff, not far from the summit of Epomeo,
about 2000 feet above the level of the sea, as also at
another place, about 100 feet below the first, on the
southern declivity of the mountain, and others still
lower, not far above the town of Moropano. At Casa-
micciol, and several places near the sea-shore, shells
have long been observed in stratified tuff and clay.
From these various points I obtained, during a short
excursion in Ischia, twenty-eight species of shells, all

of which, with one exception, were identified by M.
Deshayes with recent species**

■

It is clear, therefore, that the great mass of Epo-
meo was not only raised to its present height above
the level of the sea, but was also formed, since the
Mediterranean was inhabited by the existing species
of testacea.

In the Ischian tuffs we find pumice, lapilli, angular
fragments of trachytic lava, and other products of
igneous ejections, interstratified with some deposits of
clay free from any intermixture of volcanic matter.
These clays might have resulted from the decompo-
sition of felspathic lava like that so abundant in Ischia,
the materials having been transported by rivers and
marine currents, and spread over the bottom of the

sea where testacea were living. All these submarine
tuffs, lavas, and clays of Campania, very much.re-

* See the list of these shells, Appendix II. first ed.

Ch. X.]

OUTLINE OF COUNTRY, HOW CAUSED.

■

tain.

semble those around the base of Etna, and in parts of
the Val di Noto before described.

External configuration of the country, how caused.
When once we have satisfied ourselves by inspection of
the marine shells imbedded in tuffs at high elevations,
that a mass of land like the island of Ischia has been
raised from beneath the waters of the sea to its present
height, we are prepared to find signs of the denuding
action of the waves impressed upon the outward form
of the island, especially if we conceive the upheaving
force to have acted by successive movements. Let us
suppose the low contiguous island of Procida to be
raised by degrees until it attains the height of Ischia ;
we should in that case expect the steep cliffs which
now face Misenum to be carried upwards, and to be-
come precipices near the summit of the central moun-

Such, perhaps, may have been the origin of those
precipices which appear on the north and south sides
of the ridge which forms the summit of Epomeo in
Ischia. The northern escarpment is about 1 000 feet
in height, rising from the hollow called the Cavo delle
Neve, above the village of Panella. The abrupt man-
ner in which the horizontal tuffs are there cut off, in
the face of the cliff, is such as the action of the sea,
working on soft materials, might easily have produced,'
undermining and removing a great portion of the mass!
A heap of shingle which lies at the base of a steep
declivity on the flanks of Epomeo, between the Cavo
delle Neve and Panella, may once, perhaps, have been
a sea-beach, for it certainly could not have been brought
to the spot by any existing torrents.

There is no difficulty in conceiving that if a large
tract of the bed of the sea near Ischia should now be
gradually upheaved during the continuance of volcanic

NEWER PLIOCENE PERIOD.

[Book IV.

agency, this newly raised land might present a coun-
terpart to the Phlegraean Fields before described.
Masses of alternating lava and tuff, the products of
submarine eruptions, might on their emergence be-
come hills and islands ; the level intervening plains
might afterwards appear, covered partly by the ashes
drifted and deposited by water, and partly by those
which would fall after the laying dry of the tract.
The last features imparted to the physical geography
would be derived from such eruptions in the open
air as those of Monte Nuovo and the minor cones of
Ischia.

No signs of

Such a conversion of a

large tract of sea into land might possibly take place
while the surface of the contiguous country underwent
but slight modification. No great wave was caused by
the permanent rise of the coast near Puzzuoli in the
year 1538, because the upheaving operation appears to
have been effected by a succession of minor shocks. *
A series of such movements, therefore, might produce
an island like Ischia without throwing a diluvial rush
of waters upon low parts of the neighbouring continent.
The advocates of paroxysmal elevations may, perhaps,
contend that the rise of Ischia must have been anterior
to the birth of all the cones of loose scoriae scattered
over the Phlegraean Fields ; for, according to them, the
sudden rise of marine strata causes inundations which
devastate adjoining continents. But the absence of
any signs of such floods in the volcanic region of
Campania does not appear to me to warrant the con-
clusion, either that Ischia was raised previously to the
production of the volcanic cones, or that it may not

* See Vol. II. p. 267.

Ch. X.]

NO SIGNS OF DILUVIAL WAVES.

have been rising during the whole period of their
formation.

We learn from the study of the mutations now in
progress, that one part of the earth's surface may, for
an indefinite period, be the scene of continued change,
while another, in the immediate vicinity, remains sta-
tionary. We need go no farther than our own country
to illustrate this principle ; for, reasoning from what
has taken place in the last ten centuries, we must an-
ticipate that, in the course of the next four thousand
or five thousand years, a long strip of land, skirting the
line of our eastern coast, will be devoured by the
ocean, while part of the interior, immediately adjacent,
will remain at rest and entirely undisturbed. The'
analogy holds true in regions where the volcanic fires
are at work ; for part of the Philosopher's Tower on
Etna has stood for the last two thousand years, at the
height of more than nine thousand feet above the sea,
between the foot of the highest cone and the edge of
the precipice which overhangs the Val del Bove, whilst
large tracts of the surrounding district have been the
scenes of tremendous convulsions. The great
above has more than once been destroyed, and again
renewed ; the earth has sunk down in the neighbour-
ing Cisterna*; the cones of 1811 and 1819 have been
thrown up, on the ledge of rock below, pouring out of
their craters two copious streams of lava ; the watery
deluge of 1755, descending from the desert region
into the Val del Bove, has rolled vast heaps of rocky
fragments towards the sea ; fissures, several miles in
length, have opened on the flanks of Etna ; towns and
villages have been laid in ruins by earthquakes, or

See Vol. III. p. 425.

cone

NEWER PLIOCENE PERIOD.

[Book IV.

buried under lava and ashes ; — yet the tower has
stood, as if placed there to commemorate the stability
of one part of the earth's surface, while others in im-
mediate proximity have been subject to most wonder-
ful vicissitudes.

In concluding what I have to say of the marine and
volcanic formations of the Newer Pliocene period, I
may notice the highly interesting fact, that the marine
strata of this era have been found at great elevations,
chiefly in those countries where earthquakes have

occurred during the historical ages. On the other
\ hand, it is a still more striking fact, that there is no
j example of any extensive maritime district, now ha-
i bitually agitated by violent earthquakes, which has not,
i when carefully investigated, yielded traces of marine
strata, either of Recent or Newer Pliocene eras, at a
considerable height above the sea.

Chili — Conception Bay. — In illustration of the above
remarks, I may mention that on the western coast of
South America marine deposits occur, containing pre-
cisely the same shells as are now living in the Pacific.
In Chili, for example, as before stated, micaceous
sand, containing the fossil remains of such species as
now inhabit the Bay of Conception, are found at the
height of from- 1000 to 1500 feet above the level of the
ocean.* It is impossible to say how much of this rise
may have taken place during the Recent period. One
earthquake appears to have raised this part of the
Chilian coast, in 1750, to the height of at least twenty-
five feet above its former level. If we could suppose
a series of such shocks to occur, one in every century,
only 6000 years would be required to uplift the coast

:-*

* Vol. II. p. 256.

Ch. X.]

PERU.

1500 feet. But we have no data for inferring that so
great a quantity of elevation has taken place in that
space of time ; and although there is no evidence that
the micaceous sand may not belong to the Recent
period, I think it more probable that it was deposited
during the Newer Pliocene period.

Peru

Mr,

shanks, a naturalist who resided for several years in
South America, that in the valley of Lima, or Rimao,
where the subterranean movements have been so vio-
lent in recent times, there are indications not only
of a considerable rise of the land, but of that rise
having resulted from successive movements. Distinct
lines of ancient sea-cliffs have been observed at various
heights, at the base of which the hard rocks of green-
stone are hollowed out into precisely those forms
which they now assume between high and low water
mark on the shores of the Pacific. Immediately below
these water-worn lines are ancient beaches strewed
with rounded blocks. One of these cliffs appears in
the hill behind Banos del Pujio, about seven hundred
feet above the level of the sea, and two hundred above
the contiguous valley. Another occurs at Amancaes,
at the height of perhaps two hundred feet above the
sea ; and others at intermediate elevations.

Mr. Freyer also states that the Isle of San Lorenzo,
jn the Bay of Callao, appears to have been raised up
by volcanic action, and partially so at a comparatively
recent period ; for he found at considerable heights
above the sea the shells of Concholepas, Pecten pur-
pureus, Sigaretus concavus, and others, in great abund-
ance, retaining their colours almost as fresh as those
now living in the Pacific*

* Proceedings of Geol. Soc. No. 40. p. 179.

NEWER PLIOCENE PERIOD.

[Book IV

that the parallel roads of Coquimbo, in Chili, described
by Captain Hall, owe their origin to similar causes.
These roads, or shelves, occur in a valley six or seven
miles wide, which descends from the Andes to the
Pacific. Their general width is from twenty to fifty
yards, but they are, at some places, half a mile broad.
They are so disposed as to present exact counterparts
of one another, at the same level, on opposite sides of
the valley. There are three distinctly characterized
sets ; the upper one lies about three or four hundred
feet above the level of the sea ; the next twenty yards
lower ; and the lowest about ten yards still lower. Each
resembles a shingle beach, being formed entirely of
loose materials, principally water-worn rounded stones,
from the size of a nut to that of a man's head. The
stones are principally granite and gneiss, with masses
of schistus, whinstone, and quartz, mixed indiscrimin-
ately, and all bearing marks of having been worn by
attrition under water.*

The theory proposed by Captain Hall to explain
these appearances is the same as that which had been
adopted to account for the analogous parallel roads of
Glen Roy in Scotland. -J- The valley is supposed to
have been a lake, the waters of which stood, originally,
at the level of the highest road, until a flat beach was
produced. A portion of the barrier was then broken
down, which allowed the lake to discharge part of its
waters into the sea, and, consequently, to fall to the
second level ; and so on successively till the whole

•

* Captain Hall's South America, toI. ii. p. 9.
f See Sir T. D. Lauder, Ed. Roy. Soc. Trans., vol. ix. ; and
Dr. MacCulloch, Geol. Trans., 1st Series, vol. iv. p. 314.

Ch. X.]

PARALLEL ROADS OF COQUIMBO.

•

embankment was washed away, and the valley left as

we now see it.

As I did not feel satisfied with this explanation,
applied to my friend Captain Hall for additional details,
and he immediately sent me his original manuscript
notes, requesting me to make free use of them. In
them I find the following interesting passages, omitted

m his printed account:

" The valley is completely

open towards the sea ; if the roads, therefore, are the
beaches of an ancient lake, it is difficult to imagine a
catastrophe sufficiently violent to carry away the bar-
rier, which should not at the same time obliterate all
traces of the beaches. I find it difficult also to ac-
count for the water-worn character of all the stones,
for they have the appearance of having travelled over
a great distance, being well rounded and dressed. They
are in immense quantity too, and much more than one
could expect to find on the beach of any lake, and
seem more properly to belong to the ocean."

I had entertained a strong suspicion, before reading
these notes, that the beaches were formed by the
waves of the Pacific, and not by the waters of a lake ;
m other words, that they bear testimony to the suc-
cessive rise of the land, not to the repeated fall of the
waters of a lake. M. Boblaye has discovered four or
nve distinct ranges of ancient sea-cliffs, one above the

othe

Morea

that that country has been upheaved at as many suc-
cessive periods. He found inland terraces or beaches,
covered with shells, at the base of precipices worn like
the modern sea-cliffs by the waves, and having, like
nem, many caverns and lithodomous perforations in
tne hard limestone. *

* Jour n . de G^ol., No. x. Feb, 1831 ; Bull, de la Soc. G<5ol.
ae * ran ce, torn. ii. p. 236,

NEWER PLIOCENE PERIOD.

[Book IV*

Near the northern gate of the town of St- Mihiel,
south of Verdun, in France, I have examined a series
of markings on the face of the limestone cliffs, much

There are three and sometimes four distinct horizontal
grooves, which have been scooped out of a white semi-
crystalline rock, or marble, of the oolitic period. This
ancient cliff, which is near the right bank of the Meuse,
is in part broken into a number of detached rocks, the
upper parts of which present in some cases precipitous
sides towards all points of the compass, round which
the grooves pass in a circular course, just as if the
summit of a rocky islet had been worn by the waves,*
Captain Bayfield, in his survey of the coast of the
Gulf of St. Lawrence, traced in several places, espe-
cially in the Mingan Islands, a succession of shingle
beaches, the most distant from the shore being sixty
feet above the level of the highest tides. He also ob-
served water-worn pillars of limestone accompanying
these beaches, which bear evidence of having been
worn and scooped out at different periods ; the marks
of the successive action of the water agreeing in level
with the successive ridges of limestone shingle. The

* I have no data for speculating on the period at which these
cliffs may have emerged from the sea. I was directed to the spot,
which I visited in June, 1833, by M. Deshayes ; and 1 stated in
the second edition, on his authority, that the worn rocks were eaten
into by marine lithodomous shells, but I was unable to discover
any of these ; and I believe that the fossils of the genus Saxicava,
which M. Deshayes procured from this place, were of the age of
the corals of the limestone, not of the date of the excavation of
the grooves. The fossil corals of this formation (coral rag) fre-
quently contain lithodomous shells, which seem to have pierced
the zoophytes while they were still growing in the sea.

Ch. X.]

PARALLEL UPRAISED BEACHES.

drawings of the pillars, made to illustrate his memoir,
convince me that they are counterparts of the worn
rocks which I have seen at St. Mihiel.* I have also
been favoured with other views of rocks on the same

Fig. 1 1 o.

(see Fig. 110.)

Limestone columns in Niapisca Island, in the Gulf of St. Lawrence. Height

of the second column on the left, 60 feet.

If there exist lines of parallel upraised cliffs, we

ought to find parallel lines of elevated beaches on

tnose coasts where the rocks are of a nature to retain

or a length of time the marks imprinted on their sur-

ace. We may expect such indications to be pecu-

foT , mamfest in c °untries where the subterranean

ce has been in activity within comparatively modern

es a nd it is there that the hypothesis of paroxys-

tain e ; e ! atl0ns> and the instantaneous rise of moun-

bef " . S ' Sh ° uld first have be en put to the test,
ore lt was too hastily embraced and extended.

According to the sketch

Proceedings of Geol. Soc, No, 33. p. 5.

NEWER PLIOCENE PERIOD.

[Book IV.

•

are

given by Maclure of the geology of the Leeward
Islands, the western range consists in great part of
formations of the most modern period.* It will be
remembered, that many parts of this region have been
subject to violent earthquakes ; that in St. Vincent's
and Guadaloupe there are active volcanos, and in some
of the other islands boiling springs and solfataras. In
St. Eustatia there is a marine deposit, estimated at
1500 feet in thickness, consisting of coral limestone
alternating with beds of shells, of which the species

according to Maclure, the same as those now
found in the sea. These strata dip to the south-west,
at an angle of about 45°, and both rest upon, and are
covered by, cinders, pumice, and volcanic substances.
Part of the madreporic rock has been converted into
silex and calcedony, and is, in some parts, associated
with crystalline gypsum. Alternations of coralline
formations with prismatic lava and different volcanic
substances also occur in Dominica and St. Christo-
pher's; and the American naturalist remarks, that as
every lava-current which runs into the sea in this
archipelago is liable to be covered with corals and
shells, and these again with lava, we may suppose an
indefinite repetition of such alternations to constitute

the foundation of each island.

I do not question the accuracy of the opinion, that
the fossil shells and corals of these formations are of
recent species ; for there are specimens of limestone
in the Museum of the Jardin du Roi at Paris, from
the West Indies, in which the imbedded shells are all
or nearly all identical with those now living. Part of
this limestone is soft, but some of the specimens are
very compact and crystalline, and contain only the

* Quart. Journ. of Sci., vol. v. p. 311.

Ch. X.]

EAST INDIAN ARCHIPELAGO, ETC.

casts of shells.

«b» or sneus. Of thirty species examined by M.
Deshayes from this rock, twenty-eight were decidedly

Honduras. - Shells sent from some of the recent
strata of Jamaica, and many from the nearest adjoining
continent of the Honduras, may be seen in the British
Museum, and are indented with species now living
in the West Indian seas.

East Indian Archipelago. - We have seen that the
Indian Ocean is one of the principal theatres of vol-
camc disturbance ; it is to be expected, therefore, that
future researches in this quarter of the globe will
bring to light some of the most striking examples of
marine strata upraised to great heights during com-
paratively modern periods.

From the observations of Dr. Jack, it appears that
in the island of Pulo Nias, off the west coast of
Sumatra, masses of corals of recent species can be
traced from the level of the sea far into the interior,
where they form considerable hills. Large shells of
«ie Chama gigas ( Tridacna, Lamk.) are scattered
over the face of the country, just as they occur on the
present reefs. These fossils are in such a state of
preservation as to be collected by the inhabitants for
^purpose of being cut into rings for the arms and

Madeira.

Madeira

™een the Azores and Canaries, in both of which

Madeira

M violently shaken by earthquakes during the last
n ury. I t consists in great part of volcanic tuffs
a porous lava, intersected in some places, as at the

Geol. Trans., Second Series, vol. i. partii. p. 397.

NEWER PLIOCENE PERIOD.

[Book IV

Brazen Head, by vertical dikes of compact lava.*
Some of the marine fossil shells, procured by Mr.
Bowdich from this island, are referable to recent

species.

These examples may suffice for the present, and

lead us to anticipate with confidence, that in almost all
countries where changes of level have taken place in
our own times, the geologist will find monuments of a
prolonged series of convulsions during the Recent and
Newer Pliocene periods. Exceptions may no doubt
occur where a particular line of coast is sinking down ;
yet even here we may presume, from what we know
of the irregular action of the subterranean forces, that
some cases of partial elevation will have been caused
by occasional oscillations of level, so that modern sub-
aqueous formations will, here and there, have been
brought up to view.

I shall conclude by enumerating some exceptions to
the rule above illustrated, — instances of elevation
where no great earthquakes have been recently ex-
perienced.

Scandinavia. — The first and most important is that
of Sweden, before described.f This country, although
free from convulsions, was shown to be the theatre
of unceasing changes in the relative level of land and

sea.

marl, and clay, several hundred feet in thickness, and
containing recent species of marine shells raised to the
height of 200 feet, and even in Norway 400 feet
above the sea, and extending at some points far into

the interior.

Grosceil, near Nice.— At a spot called Grosceil, near

•i

* MS. of Captain B. Hall.

f Book ii. chap. xvii.

Ch. X.]

BORDERS OF THE RED SEA.

o c*. Hospice, a remarkable bed of fine sand occurs
at an elevation of about fifty feet above the sea.*
lhis sand rests on inclined secondary rocks, and is

Z-^Z rCmainS ° f marine s P ecies > ^11 identical

with those now inhabiting the neighbouring sea. No

less than two hundred species of shells, and several
Crustacea and echini, have been obtained by M. Risso,
in a high state of preservation, although mingled with
broken shells. The winds have blown up large heaps
of similar sand to considerable heights, upon ledges of
he steep coast farther westward; but the position of
the deposit at Grosceil cannot be referred to such
agency, for among the shells maybe seen the lar*e
Murex Triton, Linn., and a species of Cassis, weighing
a pound and a half. B

West of England. - The proofs lately brought to
ngftt ot analogous elevations of deposits containing
recent shells on our western shores, and between Lan-
cashire and the Bristol channel, have been already
pointed out.f J

Western borders of the Bed Sea. - Another excep-
tion may be alluded to, for which we are indebted to
f resear ches of Mr. James Burton. On the western

snores of the Arabian Gulf, about half way between
ue Z and Kosir6) in the 2gth degree of north latitU(Jej

tormation of white limestone and calcareous sand is
seen, reaching the height of 200 feet above the sea.
« is replete with fossil shells, all of recent species,

tth are m a beautiful state of preservation, many of

1 * examined this spot, with Mr. Murchison, in

ee des <*iption of the Map, Vol. I. p. 2 1 5.
v °t" IV,

"•

•>

1828.

NEWER PLIOCENE PERIOD.

[Book IV.

them retaining their colour,* The volcano of Gabel
Tor, situate at the entrance of the Arabian Gulf, is
the nearest volcanic region known to me at present.

But the reader must not infer, from the facts above
detailed, that marine strata of the Newer Pliocene pe-
riod have been produced almost exclusively in countries
of earthquakes, or where changes of level are known
to be taking place, as in Sweden. If our illustrations
have been drawn chiefly from modern volcanic regions,
it is simply because these formations have been made
visible in those districts only where the conversion of
sea into land has occurred in times comparatively
modern. Other continents have, during the Newer

■

Pliocene period, suffered degradation, and rivers and
currents have deposited sediment in other seas ; but
the new strata remain concealed wherever no subse-
quent alterations of level have taken place.

Yet, to a certain limited extent, the growth of new
subaqueous deposits may have been greatest where
aqueous causes have co-operated with earthquakes-
It is there that the degradation of land is most rapid,"
and it is there only that materials ejected from below,
by volcanic explosions, are added to the sediment
transported by running water.f

* These fossils are now in Mr. Greenough's museum in Lon-
don, and duplicates, presented by him, in the cabinets of the
Geological Society. A list was given in App. IL> first edition.

f See Bookii. chap. xv. ; and Bookiii. chap, xviii.

•

i •

■

■P

•

CHAPTER XL

NEWER PLIOCENE FORMATION

FRESHWATER AND

ALLUVIAL.

Valley of the Elsa

tw-a. of B „ rae _ LMSS of th ; ;~ 7 t L°Lt_ u

Con-

Osseous breccias of the Newer Pliocene era (p. 38.)- Fossil
, bones of Marsupial animals in Australian caves -Newer P lo
cenealluvmms ( P . 44.)- European alluviums chieflv tertiary"
- Erratxc blocks of the Alps - Theory of their transportation

-PmW Formations. - I N this chapter I shall treat
ot the freshwater formations, and of the cave breccias
and alluviums of the Newer Pliocene period.
In regard to the first,of these, they must have been

ormed, m greater or less quantity, in nearly all the
existing lakes of the world; in those, at least, of which
tne basins were formed before the earth was tenanted

y man If the great lakes of North America origin-
ated before that era, the sedimentary strata deposited
rem, m the ages immediately antecedent, would,

ccording to the terms of our definition, belong to the
^ewer Pliocene period.

of this

of the Elsa

As an example of the strata
sen ag6 ' Which haVe been ex P 0Sed to view in con-
thor H f e ° f the draina S e of a lak e, I may mention

Flore the Vall6y ° f the Elsa ' in Tuscan y> betw een
en ce and Sienna, where we meet with freshwater

c 2

NEWER PLIOCENE PERIOD.

[Book IV.

■

cies.

Mount

marls and travertins full of shells, belonging to species
which now live in the lakes and rivers of Italy. Val-
leys several hundred feet deep have been excavated
through the lacustrine beds, and the ancient town of
Colle stands on a hill composed of them. The subja-
cent formation consists of marine Subapennine beds,
in which more than half the shells are of recent spe-

The freshwater shells which I collected near
Colle are in a very perfect state, and the colour^ of
the Neritinae are peculiarly brilliant.*

Travertins of Rome. — Many of the travertins and
calcareous tufas which cap the hills of Rome may also
belong to the same period. The terrestrial shells in-
closed in these masses are of the same species as
those now abounding in the gardens of Rome, and the
accompanying aquatic shells are such as are found in
the streams and lakes of the Campagna. On
Aventine, the Vatican, and the Capitol, we find abund-
ance of vegetable matter, principally reeds, incrusted
with calcareous tufa, and intermixed with volcanic
sand and pumice. The tusk of a mammoth has been
procured from this formation, filled in the interior with
solid travertin, wherein sparkling crystals of augite are
interspersed, so that the bone has all the appearance
of having been extracted from a hard crystalline

rock.f

These Roman tufas and travertins repose partly on

marine tertiary strata, belonging, perhaps, to the Older
Pliocene era, and partly on volcanic tuff of a still later

* The following six pieces, all of which now inhabit Italy,
were identified by M. Deshayes ; — Paludina impura, Neritina
fiuviatilis, Succinea amphibia, Limnea auricularis, L. peregra, and
Planorbis carinatus,

f This fossil was shown me by Signer Biccioli at Rome.

Ch. XI.] LOESS OF THE VALLEY OF THE RHINE

date. They must have been formed in small lakes and
marshes, which existed before the excavation of the
valleys, which divide the seven hills of Rome, and they
must orginally have occupied the lowest hollows of the
country as it then existed ; whereas now we find them
placed upon the summit of hills about 200 feet above
the alluvial plain of the Tiber. We know that this
nver has flowed nearly in its present channel ever
since the building of Rome, and that scarcely any
changes in the geographical features of the country
have taken place since that era.

Whe

formed, those of Monte Mario for example, the Medi-
terranean was already inhabited by a large proportion
of the existing species of testacea. At a subsequent
period, volcanic erruptions occurred, and tuffs were
superimposed. The marine formation then emerged
from the deep, and supported lakes wherein the fresh-
water groups above described slowly accumulated, at
a time when the mammoth inhabited the country,
lne valley of the Tiber was afterwards excavated, and
the adjoining hills assumed their present shape ; and
then a long interval may, perhaps, have elapsed before
the first human settlers arrived. Thus we have evi-
dence of a chain of events, all regarded by the geolo-
gist as among the most recent, but which, nevertheless,
may have preceded, for a long series of ages, a very
remote era in the history of nations.

of the valley of

A remarkable

Having re-examined a much greater extent of the country
covered by the loess in the years 1833 and 1835, I have modified
and retracted some opinions which I expressed in regard to it in
former editions. For a full account of my observations see
Jameson's Ed. New Phil. Journ., No. 33, July 1834.; Pro-

c 3

r '

NEWER PLIOCENE PERIOD.

[Book IV.

deposit of ancient silt, containing land and freshwater
shells of living European species, occurs, here and
there, throughout the valley of the Rhine, from the
plains below Cologne up to the borders of Switzerland,
near SchafFhausen, and in the valleys of the principal
tributaries of the Rhine. This deposit of yellow cal-
careous loam is provincially termed " loess " by the
Germans, and in Alsace "lehm," and it partakes
partly of an alluvial and partly of a lacustrine cha-
racter. It exhibits almost every where the same mi-
neralogical characters and fossil shells, and is usually
found in detached patches, but sometimes forming
lines of low hills which rest on the gravel of the allu-
vial plain of the Rhine. Occasionally it reposes on
the flanks of the mountains bounding the great valley,
where it rises to various elevations above the
sometimes to 300 or 400 feet, as near Basle, where it
is more than 1 200 feet above the sea.

e Duchy of

Darmstadt by Mayence, Oppenheim, Alzey, Flonheim,
Eppelsheim, and Worms, I found the loess spread al-
most every where over the country. On the opposite
side of the Rhine, in the elevated table land above the
Bergstrasse between Wiesloch and Bruchsal, I ob-
served it attaining a thickness of 200 feet. It extends
also far into Wurtemberg, up the valley of the Neckar,
and from Frankfort, up the valley of the Mayne, to
above Dettelbach. Near Strasburg large masses of it
are seen at the foot of the Vosges mountains, on the
left of the great plain of the Rhine, and at the base of
the mountains of the Black Forest on the other side-

river,

In an excursion

through part of th

eeedings of Geol. Soc, No. 36. p. 83., and No. 43. p, 221, ; and
Anniv. Address to Geol. Soc. 1 836.

Helix

Ch. XI.] LOESS OF THE VALLEY OF THE RHINE. 31

It occurs not only at Basle, as above stated, but still
higher up the Rhine at Waldshut, and it is said to
terminate between that place and Schaffhausen. It
is important to remark that all the above-mentioned
places, however distant from each other, have a direct

hydrographical communication with the main valley
of the Rhine.

When the loess is first observed lying on the gravel
of the great plain near Bonn, Heidelberg, Strasburg,
and other places, we naturally suppose it to be of very
modern origin, especially as it contains recent land
and freshwater shells of species which are, for the
most part, very abundant in the adjacent country.
Even the colour of some of these shells, as that of the

moralis, is occasionally preserved. But, when
we have extended our investigations, we find that al-
though the present system of hills and valleys must
have existed previously to the formation of the loess,
yet the whole country has undergone many great geo-
raphical changes during the accumulation of the de-

so great, indeed, that there has probably been
a sinking down to the amount of many hundred feet,
and afterwards a re-elevation of all the land between
Switzerland and Holland since this silt began to accu-
mulate. No changes of less magnitude seem adequate
to explain the phenomena about to be described.

The loess at Heidelberg, according to M. Leon-
hard, consists chiefly of argillaceous matter, combined
with a sixth part of carbonate of lime, and a sixth of
quartzose and micaceous sand. It is a pulverulent
loam, of a dirty yellowish-grey colour, often containing
calcareous sandy concretions or nodules, rarely ex-
ceeding the size of a man's head. Its entire thickness,
in some places, amounts to between 200 and 300 feet;

posit

NEWER PLIOCENE PERIOD.

[Book IV.

yet there are often no signs of stratification in the
mass, except here and there at the bottom, where there
is occasionally a slight intermixture of drifted materials
derived from subjacent rocks.

As the pure loess exhibits no division into strata,
I at first imagined, in common with other observers,
that this deposit was thrown down suddenly from the
muddy waters of a transient flood, in the same manner

as the moya of the Andes, or as the trass of the Rhine
volcanos is generally believed to have been formed.
But on re-examining the places where loess and allu-
vium, or loess and layers of volcanic matter, alternate,
I am compelled to renounce this view. In the deep
gravel pits without the Manheim gate of Heidelberg,
loess is seen interstratified with gravel ; and here more
than one bed containing entire land and freshwater
shells rests upon, and is covered by, a stratum of

gravel, showing the effects of successive accumulation.
I observed the same fact in the valley of the Lahn
north of Limburg, near the village of Elz ; and Pro-
fessor Bronn informs me, that the calcareous concre-
tions of the loess are sometimes arranged in horizontal
layers, marking a difference in the carbonate of lime
with which the sediment must have been charged at
different periods.

It should also be observed that many of the ter-
restrial and aquatic shells preserved in this silt are of
the most fragile and delicate structure, and must, for
the most part, have been broken to-pieces if they had
been swept along by a violent inundation of force suf-
ficient to transport pebbles; whereas the shells are
almost invariably perfect and uninjured, even in those
places where the loamy beds of loess alternate with
gravel.

Ch. XI.]

LOESS OF THE VALLEY OF THE RHINE.

The most widely spread and abundant fossils in this

Fig. Ill

Helix plebeium

(see Figs.

Fig. 112.

Fig. 113

Succinea elongata. Pupa muscorum.

Helix plebeium.

tioned shell is amphibious, and such as may have been

washed away from the banks of streams during floods.
The proportion of land shells of the genera Helix, Pupa,
and Bulimus, is very large ; but in many places aquatic
species of the genera Limnea, Paludina, and Planorbis
are also found. I have never detected the Unio or
Neritina among the rest, but, with these exceptions,
there is a great generic resemblance between the as-
semblage of fossils in the loess and the shells which
the Rhine carries down in our own time to the sea.
With a view of ascertaining this point I collected, in
the summer of 1833, several hundred shells, which
were exposed on the margin of the Rhine on the fall
of the waters, or had been cast ashore by large waves
raised by the steam boats ; and they proved to be, for

Heh

Manorbis, which may have been washed away during
floods from pools and marshes bordering the river.

Bones of vertebrated animals are rare in the loess,
but those of the mammoth, horse, and some other
quadrupeds have been met with. At the village of
tfmningen, and the hills called Bruder Holz, _
as le,' I found the vertebrae of fish together with the

near

usual shells.

c 5

NEWER PLIOCENE PERIOD.

[Book IV.

belong decidedly to the Shark family, perhaps to the
genus Lamna ; and although it seemed, at first, extra-
ordinary that they should occur among land and fresh-
water shells, I am informed, in explanation of the fact,
that certain fish of this family ascend the Senegal,
Amazon, and other great rivers, to the distance of
several hundred miles from the ocean.*

The reader is probably aware that on both sides of
the Rhine, between Bonn and Coblentz, there is a
region of extinct volcanos. Now, on visiting part of
this country, near Andernach, and examining the
sections which have been well described by MM.
Steininger, Hibbert, and others, I perceived clear evi-
dence that some of the last volcanic eruptions of the
Lower Eifel took place both during and since the de-
position of the loess. The loamy sediment may be
seen in the Kirchweg, above Andernach, alternating
with volcanic matter, over which is a mass of pure
and unmixed loess, thirty feet and upwards in thick-
ness, containing the usual shells ; and over the whole
are strewed layers of pumice, lapilli, and volcanic sand,
from ten to fifteen feet thick, very much resembling
the ejections under which Pompeii lies buried. There
is no passage at this upper junction from the loess into
the pumiceous superstratum ; and this last follows the
slope of the hill, just as it would have done had it
fallen in showers from the air on a declivity partly
formed of loess.

In general, however, the loess overlies almost all the
volcanic products, even those between Neuwied and
Bonn, which have the most modern aspect ; and it has
filled up in part the crater of the Roderberg, a volcanic

* Proceedings of Geo!. Soc. No. 43. p. 222.

Ch. XL] LOESS OF THE VALLEY OF THE RHINE.

hill near Bonn. It was in 1833 that a well was sunk at
the bottom of this crater through seventy feet of loess,
in part of which were the usual calcareous concre-

tions.

It has been ascertained that the waters of the Rhine,
when evaporated, leave a residuum of calcareous loam,
not distinguishable from loess * ; so that if these waters
should now overflow the low lands adjoining the river,
they might give rise to a deposit having the same
mineral characters as the loess, and which would con-
tain, as I have already shown (p. 33.), fossil shells for
the most part of the same genera.

The first idea which has probably occurred to every
one, after examining the loess between Mayence and
Basle, is, to imagine that a great lake once extended
throughout the valley of the Rhine between those two
places. Such a lake may have sent off large branches
up the course of the Mayne, Neckar, and other tri-
butary valleys, in all of which large patches of loess
are now seen. The barrier of the lake might be placed
somewhere in the narrow and picturesque gorge of the
Rhine between Bingen and Bonn. But this theory is
insufficient to explain the phenomena ; for that gorge
itself has once been filled with loess, which must have
been tranquilly deposited in it, as also in the lateral
valley of the Lahn, communicating with the gorge.
The loess has also overspread the high adjoining plat-
form near the village of Plaidt, above Andernach.
Nay, on proceeding farther down to the north, we
discover that the hills which skirt the valley between
Bonn and Cologne have loess on their flanks, which

fc>ee Mr. Horner, on the Sediment of the Rhine : Proceed-
ings of Geol. Soc. 1 834.

c 6

NEWER PLIOCENE PERIOD.

CBook IV .

also covers here and there the gravel of the plain as
far as Cologne.

Besides these objections to the lake theory it will be
remembered, that the loess is met with near Basle,
capping hills more than 1200 feet above the sea, so
that a barrier of land capable of separating the sup-
posed lake from the ocean would require to be at least
as high as the mountains called the Siebengebirge,
near Bonn, the loftiest summit of which, the Oehlberg,
is only 1209 feet above the Rhine and 1369 feet above
the sea. It would be necessary, moreover, to place
this lofty terrier somewhere below Cologne, that is to
say, precisely where the level of the land is now lowest

Instead, therefore, of supposing one continuous lake
of sufficient extent and depth to allow of the simul-
taneous accumulation of the loess, at various heights,
throughout the whole area where it now occurs, I
conceive that, subsequently to the period when the
countries now drained by the Rhine and its tributaries
acquired nearly their actual form and geographical
features, they were again depressed gradually by a
movement like that now in progress on the west coast
of Greenland. In proportion as the whole district was
lowered, the general fall of the waters between the
Alps and the ocean was lessened; and both the main
and lateral valleys, becoming more subject to river
inundations, were partially filled up with fluviatile
silt, containing land and freshwater shells. When a

thickness of many hundred feet of loess had been
thrown down slowly by this operation, the whole region
was once more upheaved gradually, but perhaps not
equally in all parts. During this upward movement most
of the fine loam would be carried off by the denuding
power of rains and rivers ; and thus the original valley*

Ch. XI.] LOESS OF THE VALLEY OF THE RHINE.

may have been re-excavated, and the country almost
restored to its pristine state, with the exception of
some masses and patches of loess still remaining,
which, from their frequency and remarkable homoge-
neousness of composition and fossils, attest the ancient
continuity and common origin of the whole. By in-
troducing such general fluctuations of relative level,
we dispense with the necessity of erecting, and after-
wards removing, a mountain barrier sufficiently high
to exclude the ocean from the valley of the Rhine
during the period of the accumulation of the loess.

The hypothesis above suggested may, perhaps, be
better understood if we consider what would happen
if similar alterations of level should occur in another

part of the world.

(Vol. I. p. 290.)

that several large lakes have recently been formed in
the basin of the Red River, in Louisiana, and that trees
are still standing there under water. One of these
lakes is no less than thirty miles long, into which, as
into others, the waters of the Red River flow up dur-
ing floods, the main stream at such seasons invading
some of the valleys of its tributaries. Whatever
may be the causes of this singular state of things
in Louisiana, it is clear that analogous effects might
arise from partial depressions of land. It is also evi-
dent that if a general subsidence should take place in
the hydrographical basin alluded to, the fall of the
waters between the Rocky Mountains and the ocean
would be lessened, and, consequently, there would be
an increased liability to river inundations in all the
plains and valleys of the same basin. Under these cir-
cumstances, the red ochreous sediment from which the
Red River derives its name would be deposited in the
main an <* partially in the lateral valleys ; and as the

■ ■

NEWER PLIOCENE PERIOD.

[Book IV.

course of the Red River is double in length that of
the Rhine, the area covered by red fluviatile silt might
be vast in proportion. It may also be observed that
the number of temporary lakes and marshes, occa-
sioned by frequent overflowings and partial subsidences
of land, would favour greatly the growth of amphibious
mollusks of the genus Succinea; while, at the same
time, land and freshwater shells would annually be
swept away and imbedded in mud, which, like that of
the Nile in Egypt, would be thrown down periodically
on the plains. The thickness of the muddy deposits
would depend on the quantity of time during which

the country continued to sink, provided the rate of
sinking be sufficiently slow to allow of the water being
charged again and again with fresh sediment. The re-
elevation of the district at a subsequent period would
be attended with extensive denudation, or removal of

fine sediment. The colour of the loam might, in this in-
stance, be as uniformly red as it is yfellow in the valley
of the Rhine ; while, in other respects, the phenomena
would be analogous, and such as might appear, at first
sight, to indicate the former existence of an enormous
lake more than 1000 feet deep and several hundred
miles in length.* ^^M

Osseous breccias

Sicily.

The breccias latel

found in several caves in Sicily belong evidently to
the period under consideration. I have shown, in the
sixth chapter, that the cavernous limestone of the
Val di Noto is of very modern date, as it contains a
great abundance of fossil shells of recent species ; and

* For particulars concerning the loess of the Rhine, consult
the works of MM. Bronn, Leonhard, Boue, Voltz, Noeggerath,
Steininger, Merian, Rozet, Von Meyer, Hibbert, and Horner.

• ;

•••

Ch. XI.]

BRECCIAS »IN SICILIAN CAVES.

if any breccias are found in the caverns of this rock,
they must be of still later origin. *

We are informed by M. Hoffmann, that the bones
of the mammoth, and of an extinct species of hippo-
potamus, have been discovered in the stalactite of
caves near Sortino, of which the situation is repre-
sented in the annexed diagram at b. The same au~

e. 114

a. Alluvium, 1

b, b. Deposits in caves, J contalllin g remains of extinct quadrupeds.

C. Limestone containing remains of recent shells.

thor also describes a breccia, containing the bones of
an extinct rhinoceros and hippopotamus, in a cave in
the neighbourhood of Syracuse, where the country
is composed entirely of the Val di Noto limestone.
Some of the fragments in the breccia are perforated
by lithodomi, and the whole mass is covered by a
deposit of marine clay filled with recent shells. *
These phenomena may, I think, be explained by sup-
posing such oscillations of level as are known to occur

on maritime coasts where earthquakes prevail ,

m fact, as have been witnessed on the shores of the
Bay of Baiae within the last three centuries, f For
*t is evident that the temporary submergence of a
cave filled with osseous breccia might afford time for

Hoffmann, Archiv fiir Mineralogie, p. 393. Berlin, 1831.

such,

Dr.

Christie, Proceedings of Geol. Soc, No. xxiii. p. 333
t Vol, II. p. 267,

I
I

NEWER PLIOCENE PERIOD.

[Book IV.

the perforation of the rock by boring testacea, and
for the deposition upon it of mud, sand, and shells.

The association in these and other localities of
shells of living species with the remains of extinct
mammalia is very distinct, and corroborates the in-
ference adverted to in a former chapter, that the lon-
gevity of species in the mammalia is, upon the whole,
inferior to that of the testacea. I am by no means
inclined to refer this circumstance to the intervention
of man, and his power of extirpating the larger qua-
drupeds ; for the succession of mammiferous species
appears to have been in like manner comparatively

a. Monte Grifone.

b. Cave of San Ciro. *

c. Plain of Palermo, in which are Newer Pliocene strata of

limestone and sand.

d. Bay of Palermo.

rapid throughout the older tertiary periods. Their
more limited duration depends, in all probability, on
physiological laws, which render warm-blooded qua-
drupeds less capable, in general, of accommodating
themselves to a great variety of circumstances, and,
consequently, of surviving the vicissitudes to which the
earth's surface is exposed in a great lapse of ages, f

* Section given by Dr. Christie, Edin. New Phil. Journ.,
No. xxiii., called by mistake the Cave of Mardolce, by the late
M. Hoffmann. See account by Mr. S. P. Pratt, F.G.S., Pro-
ceedings of Geol. Soc. No. 32. 1833.

t See Vol. III. p. 100., and book i. chap. vi.

•

Ch. XL]

BRECCIAS IN SICILIAN CAVES.

Caves near Palermo. — The caves near Palermo
exhibit appearances very analogous to those above

described

information has been

lately published respecting them. According to Hoff-
mann, the grotto of San Giro is distant about two
Wiles from Palermo, and is twenty feet high and ten
wide. It Occurs in a secondary limestone, in the
Monte Grifone, at the base of a rocky precipice about
180 feet above the sea. From the foot of this preci-
pice an inclined plane, consisting of horizontal tertiary
strata, of the Newer Pliocene period, extends to the
sea, a distance of about a mile.

The limestone escarpment was evidently once a
sea-cliff, and the ancient beach still remains formed of
pebbles of various rocks, many of which must have
been brought from places far remote. Broken pieces
of coral and shell, especially of oysters and pectens,
are seen intermingled with the pebbles. Immediately
above the level of this beach, serpulse are still found
adhering to the face of the rock, and the limestone is
perforated by lithodomi. Within the grotto, also, at
tne same level, similar perforations occur; and so
numerous are the holes, that the rock is compared by
Hoffmann to a target pierced by musket balls,
in order to expose to view these marks of boring-shells
J n the interior of the cave, it was necessary first to re-
move a mass of breccia, which consisted of numerous

■A*

ragments of rock and an immense quantity of bones
imbedded in a dark brown calcareous marl. Many of
the bones were rolled as if partially subjected to the

But

action of the

waves. Below this breccia, which is

about twenty feet thick, was found a bed of sand filled
Wl th sea-shells of recent species ; and underneath the
and, again, is the secondary limestone of Monte Gri-
fone. The state of the surface of the limestone in the

NEWER PLIOCENE PERIOD.

[Book IV.

cave above the level of the marine sand is very differ-
ent from that below it. Above, the rock is jagged and
uneven, as is usual in the roofs and sides of limestone
caverns ; below, the surface is smooth and polished, as
if by the attrition of the waves.

So enormous was the quantity of bones, that many
ship-loads were exported in the years 1829 and 1830,
in the hope of their retaining a sufficient quantity of
gelatine to serve for refining sugar : for which, how-
ever, they proved useless. The bones belong chiefly
to the mammoth (E. primigenius), and with them are
those of an hippopotamus, distinct from the recent
species, and smaller than that usually found fossil.
Several species of deer, also, and, according to some
accounts, the remains of a bear, were discovered.

It is easy to explain in what manner the cavern of
San Ciro was in part filled with sea-sand, and how the

surface of the limestone became perforated by litho-
domi; but in what manner, when the elevation of the
rocks and the ancient beach had taken place, was the
superimposed osseous breccia formed ? For want of
more exact local details, it would be rash to speculate
on this subject ; but by referring to what was previ-
ously said of caverns near the sea-shore of the Morea,
from which rivers escape, the reader may conceive
that caves, after having been submerged and filled
with sea-sand, may afterwards be upraised and flooded
by the waters of engulphed rivers
animal remains from the land. #

Two other caverns are described by Dr. Christie as
occurring in Mount Beliemi, about four miles west of
Palermo, at a higher elevation than that of San Ciro,
being more than three hundred feet above the level of

* See Vol. III. p. 206.

washing down

•

_^^*^H

Ch. XL]

AUSTRALIAN CAVE-BRECCIAS.

)

the sea. In one of these places the bones are found
only in a talus at the outside of the cavern ; in the
other, they occur both within the cave and in the talus
which slopes from it to the plain below. These caves
appear to be situated much above the highest point
attained by the tertiary deposits in this neighbourhood ;
nor is there the slightest appearance in the caves
themselves of the sea having been there.*

Australian cave-breccias. — Ossiferous breccias have
lately been discovered in fissured and cavernous lime-
stone in Australia, and the remains of the fossil mam-
malia are found to be referable to species now living in
that country, mingled with some relics of extinct animals.

Some of these caves have been examined by Major
Mitchell, in the Wellington Valley, about 210 miles
west of Sydney, on the river Bell, one of the principal
sources of the Macquarie, and on theMacquarie itself.

The fissures and caverns appear to correspond
closely with those which contain similar osseous brec-
cias in Europe ; they often branch off in different
directions through the rock, widening and contracting
their dimensions^ the roofs and floors being covered
with stalactite. The bones are often broken, but do
not seem to be water-worn. In some caves and fissures
they lie imbedded in loose earth, but usually they are in-
cluded in a breccia, having aredochreous cement as hard
as limestone, and like that of the Mediterranean caves.

The remains found most abundantly are those of
the kangaroo. Amongst others, those of the Wombat,
Dasyurus, Kaola, and Phalangista, have been recog-
nized. The greater part of them belong to existing^
but some to extinct, species. One of the latter bones,

Dr. T. Christie, Jameson, Edin. New Phil. Jour., No. xxiii.

p. 1.

** •*-!**

NEWER PLIOCENE PERIOD.

[Book IV

of much greater size than the rest, is supposed, by
Mr. Clift, to belong to an hippopotamus- *

In a collection of these bones sent to Paris, Mr. Pent-
land thought he could recognize a species of Halma-

■

turus, exceeding in size the largest living kangaroo, f

These facts are full of interest, for they prove that
the peculiar type of organization which now character-
izes the marsupial tribes has prevailed from a remote
period in Australia ; and that in that continent, as in
Europe, North and South America, and India, some
species of mammalia have become extinct. It also
appears, although the eyidence on this point is still
incomplete, that among the extinct were land qua-
drupeds far exceeding in magnitude any of the wild
animals now inhabiting New Holland. J

Newer Pliocene Alluviums.

Some writers have

attempted to introduce into their classification of

geological periods an alluvial epochs as if the trans-
portation of loose matter from one part of the surface
of the land to another had been the work of one par-
ticular period.

With equal propriety might they have endeavoured
to institute a volcanic period, or a period of marine
or freshwater deposition ; for alluvial formations must
have originated in every age, since the surface of the
earth was first divided into land and sea, but most
rapidly in any given district at those periods when

* Mr. Clift, Edin. New Phil. Journ., No. xx. p. 394. Major
Mitchell, Proceedings of Geol. Soc, 1831, p. 321.

f Journ. de Geologie, tome iii. p. 291. The bone mentioned
as that of an 'elephant by Mr. Pentland, was the same large bone
alluded to by Mr. Clift.

f For remarks on the mode in which these caverns may have
been filled with osseous breccias, see Vol. III. p. 203.

Ch. XL]

NEWER PLIOCENE ALLUVIUMS.

land has been upheaved above, or depressed below,
its former level.*

If those geologists who speak of an "alluvial epoch"
intend merely to say that a great part of the Euro-
pean alluviums are tertiary, there may undoubtedly
be much truth in the opinion ; for the larger part of
the existing continent of Europe has emerged from
beneath the waters during some one or other of the
tertiary periods + ; and it is probable, that even those
districts which were land before the commencement
of the tertiary epoch, may have shared in the subter-
ranean convulsions by which the levels of adjoining
countries have since been altered. During such sub-
terranean movements new alluviums might be formed
in great abundance, and those of more ancient date so
modified as to retain scarcely any of their original
distinguishing characters.

During the gradual rise of a large area, first from
beneath the waters, and then to a great height above
them, several kinds of superficial gravel must be
formed and transported from one place to another.
When the first islets begin to appear, and the breakers
are foaming upon the new raised reefs, many rocky frag-
ments are torn ofF and rolled along the bottom of the sea.

Let the reader recall to mind the action of the tides
and currents off the coast of Shetland, where blocks
of granite, gneiss, porphyry, and serpentine, of enor-
mous dimensions, are continually detached from wast-
mg cliffs during storms, and carried in a few hours to
a distance of many hundred yards from the parent
rocks. % Suppose the floor of the ocean, after being

See definition of alluvium, Vol. III. p. 196.
f See map, Vol. I. p. 214.
i See Vol. I. p. 391.

NEWER PLIOCENE PERIOD.

[Book IV.

thus strewed over with detached blocks and pebbles,
to be converted partially into land, the geologist might
then, perhaps, search in vain for the masses from
which the fragments were originally derived, since part
of these may have been consumed by the waves, and
the rest may remain submerged beneath them.

If this new land be then uplifted to a considerable
height, the marine alluvium before alluded to would
be raised up on the summits of the hills and on the
surface of elevated platforms. It might still constitute
the general covering of the country, being wanting
only in such valleys and ravines as may have been
caused by earthquakes, or excavated by the power of
running water during the rise of the land : for the
alluvium in those more modern valleys would consist
partly of pebbles washed out of the older gravel be-
fore mentioned, but chiefly of fragments derived from
the rocks which were removed during the erosion of

the valleys themselves.

.Erratic blocks. — Blocks of extraordinary magnitude
have been observed at the foot of the Alps, and at
a considerable height in some of the valleys of the
Jura, exactly opposite the principal openings by which
great rivers descend from the Alps. These fragments
have been called « erratic," and many imaginary causes
have been invented to account for their transport-
ation. Some have talked of chasms opening in the
ground immediately below, and of huge fragments
having been cast out of them from the bowels of the

■

earth. Others have referred to the deluge, an agent
in which a simple solution is so often found of every
difficult problem exhibited by alluvial phenomena;
and more recently, the sudden rise of mountain-chains
has been introduced as a cause which may have given
rise to diluvial waves, capable of devastating whole

♦

Ch. XI.]

ERRATIC BLOCKS.

the^T' and dHftin S hu §e blocks from one part of
tne^earth s surface to another.

formptf emS * ecessai 7 t0 suppose that the Jura once

-ents o? SZf ? ' thC ^ »* ^^ ^~
thp Ai • ' atarem ote period, detached from

nlatfo e T mitS ' and tran ^rted to lower hills or

\ZT\ ° h WGre destined af terwards to be up-
aised and to form the independent chain now called

coltZ\ 1^ * haS b6en ° ften su §g^ted, may have

some of h ^ "' t0 the ^^ ° f Such blocks * f°r
flood vl ? MaSSeS me S ° enormo ^ that not even a
flood hke that in the valley of Bagnes, in 1818*, can

be supposed to have conveyed them to considerable
distances by the power of water alone.

That the Alps must have been moved and shaken

ZiZl f 9 " t * Peri ° ds com P ara tively modern, is
evident from the fact that they are skirted on their

northern, southern, and eastern flanks by marine ter-

tiary strata. When these were raised into their present

Position, to the height of many hundred feet above the
sea the whole of ^ ^ chain ^ ^

Pated in the convulsions.
It is important, therefore, to consider what would
ow happen if regions like that of Mont Blanc were

d!tff !i t° earth( l uak es- Large fragments of rock,
Cached by the action of rain and frost from the
peaks or "needles," as they are called, of Chamouni,
11 annually on the surface of the glaciers, and are
leal? • tranS P° rted b y ^ to the distance of many
mvtT 8 ! nt ° thG Valle ^ S below -t The shock of an

simiWh ? rf thr ° W d ° Wn a P rodi S ious load of
lanch (■ heavier masses, accompanied by ava-

es of snow and ice, by which the moraine of the

Se e Vol. I. p . 295.

+ Vol. I. p. 269

NEWER PLIOCENE PERIOD.

[Book IV.

glacier would be greatly enlarged. If the shocks took
place on the eve of a thaw in spring, when the accu-
mulated snows of winter were beginning to melt, they
would cause almost every where immense avalanches,
by which many narrow gorges might be choked up, so
that the valleys above such barriers of snow, ice, and
rock would be converted into lakes. Portions of the
rent glaciers, moreover, would at their lower extre-
mities be covered with water, and might be floated
off together with incumbent and included fragments of
rock. At length, on the bursting of the temporary
barrier, the whole mass of waters, together with huge
rocks buoyed up by ice, would descend with tremen-
dous violence into the lower country.

The manner in which the ice of rivers and of the
sea itself contributes, in the Baltic and other northern
regions, to transport large blocks, as well as sn
pieces of stone, to vast distances, has been treated of

in a former chapter.f

Assuming, then, that almost all the Eu-
ropean alluviums are tertiary, we have next to inquire
which of them are of Newer Pliocene origin. It is
clear that, when a district like the Val di Noto, is
composed of rocks of this age, all the alluvium upon
the surface must necessarily belong either to the
Newer Pliocene or the Recent epoch. If, therefore,
the elevation of the mountains of the Val di Noto was
chiefly accomplished antecedently to the Recent epoch,
we must at once pronounce all alluviums, in the posi-
tion indicated at a, Fig. 114. (p. 38.), to belong to the
Newer Pliocene era. I saw gravel so situated at
Grammichele in Sicily, and was informed that it con-
tained the bones of the mammoth.

aller

Sicily.

* See Vol. I. p. 271

CHAPTER XII.

OLDER PLIOCENE FORMATIONS.

eoiogical monuments of the older Pliocene period — Subapen-
nine formations — Opinions of Brocchi — Different groups
er med by him Subapennine are not all of the same age
Mineral composition of the Subapennine formations — Marls

Subapennine beds, how formed

Yellow sand and gravel

\P» 56.) — Illustration derived from the Upper Val d'Arno
^ r ganic remains of Subapennine hills — Older Pliocene strata
a t the base of the Maritime Alps — Genoa (p. 63.) — Sa-

v ona

nan
the J

Albenga

Nice

Conglomerate of Valley of Mag-

Its origin — Tertiary strata at the eastern extremity of

yrenees.

Sub

a pennine strata. — We must now carry our re-
spect one step farther, and treat of the monuments
9 *he era immediately antecedent to that last con-
ned. The Apennines, it is well known, are com-
V Se d chiefly of secondary rocks, forming a chain which
inches off from the Ligurian Alps and passes down
he middle of the Italian peninsula. At the foot of
ese mountains, on the side both of the Adriatic and
® Mediterranean, are f° un d a series of tertiary strata
*ch form, for the most part, a line of low hills occu-
rjuig the space between the older chain and the sea.
0cc hi, the first Italian geologist who described this

Hewe

it the name of the

group in detail, gave *» *™ .«***^ ~~ —
Apennines ; and he classed all the tertiary strata of

Italy f ro

m Piedmont to Calabria, as parts of the same

•/Stem. Certain mineral characters, he observed, were

vol. Iv .

OLDER PLIOCENE PERIOD.

[Book IV.

common to the whole ; for the strata consist generally
of light brown or blue marl, covered by yellow calca-
reous sand and grave]. There are also, he added, some
species of fossil shells which are found in these de-
posits throughout the whole of Italy.

In a catalogue, published by Lamarck, of five hun-
dred species of fossil-shells of the Paris basin, a small
number only were enumerated as identical with those
of Italy, and only twenty as agreeing with living spe-
cies. This result, said Brocchi, is wonderful, and verv
different from that derived from a comparison of the

half of

species now living in the Mediterranean, or in other
seas chiefly of hotter climates.*

He also stated, that it appeared from the observ-
ations of Parkinson, that the clay of London, like that
of the Subapennine hills, was covered by sand (alludino-
to the crag), and that in that upper formation of sand
in England the species of shells corresponded much
more closely with those now living in the ocean than
did the species of the subjacent clay. Hence he in-
ferred that an interval of time had separated the origin
of the two groups. But in Italy, he goes on to say,
the shells found in the marl and superincumbent sand
belong entirely to the same group, and must have been
deposited under the same circumstances, f

Notwithstanding the correctness of these views
Brocchi conceived that the Italian tertiary strata, as a
whole, might agree with those of the basins of Paris
and London ; and he endeavoured to explain the dis-
eordance of their fossil contents by remarking, that the

>•

* Conch. Foss. Subap., torn. i. p. 14s.
t Ibid., p. 147.

Ch.XlL]

SUBAPENNINE STRATA.

Med

ivmg m the ocean. * In attempting thus to assimilate

le age of these distinct groups,, he was evidently in-

uenced by his adherence to the anciently received

theory of the gradual fall of the level of the ocean, to

which, and not to the successive rise of the land, he

attributed the emergence of the tertiary strata ; all of

nch he consequently imagined to have remained

under water down to a comparatively recent period.

Brocchi was perfectly justified in affirming that there

Wer e some species cf shells common to all the strata

called by him Subapennine; but I have shown that this

* ac t is not inconsistent with the conclusion, that the

Sev eral deposits may have originated at different pe-

ri °ds, for there are species of shells common to all the

ertiary eras. He seems to have been aware, however,

the insufficiency of his data ; for in giving a list of

s pecies universally distributed throughout Italy, he

^ndidly admits his inability to determine whether the

^ells of Piedmont were all identical with those of

uscany, and whether those of the northern and south-

n extremities of Italy corresponded, f

We have already satisfactory evidence that the

a pennine beds of Brocchi belonged, at least, to

Sub

Miocene

thr ee periods.

°J the strata of Piedmont, those of the hill of the

u perg a? for example; to the Older Pliocene belong the

greater part of the strata of northern Italy and of

uscany, and perhaps those of Rome; to the Newer

] ocene, the tufaceous formations of Naples, the cal-

Careous strata of Otranto, and probably the greater

P ar t of the tertiary beds of Calabria.

Conch. Foss. Subap., torn. i. p. 166.

t Ibid., p. 143

D 2

OLDER PLIOCENE PERIOD,

[Book IV.

That there is a considerable correspondence in the
arrangement and mineral composition of these different

■

Italian groups, is undeniable ; but not that close re-
semblance which should lead us to assume an exact
identity of age, even had the fossil remains been less
dissimilar.

Very erroneous notions have been etertained re-
specting the contrast between the lithological charac-
ters of the Italian strata and certain groups of higher
antiquity. Dr. MacCulloch has treated of the Italian
tertiary beds under the general title of " elevated
submarine alluvia;" and the overlying yellow sand
and gravel may, according to him, be wholly, or in
part, a terrestrial alluvium. * Had he visited Italy, I
am persuaded that he would never have considered the
tertiary strata of London and Paris as belonging to
formations of a different order from the Subapennine
groups, or as being more regularly stratified. He
seems to have been misled by Brocchi's description,
who contrasts the more crystalline and solid texture of
the older secondary rocks of the Apennines with the
loose and incoherent nature of the Subapennine beds,
which resemble, he says, the mud and sand now de-
posited by the sea.

I have endeavpured, in a former chapter, to restrict
within definite limits the meaning of the term allu-
vium \ ; but if the Subapennine beds are to be de-
signated " marine alluvia," the same name might,
with equal propriety, be applied not only to the argil-
laceous and sandy groups of the London and Hamp-
shire basins, but to a very great portion of our se-

* Syst. of Geol., vol. i. chap. xv.
f Vol. III. p. 196.

Ch -xn.]

SUBAPENNINE MARLS.

con-

condary series, where the marls, clays, and sands are
as imperfectly consolidated as are the tertiary strata
ot Italy in general.

They who have been inclined to associate the idea
o the more stony texture of stratified deposits with a
comparatively higher antiquity, should consider how

issimilar, in this respect, are the tertiary groups of
•London and Paris, although admitted to be of
temporaneous date ; or they should visit Sicily, and
behold a soft brown marl, identical in mineral cha-
racter with that of the Subapennine beds, underlying
a mass of solid and regularly stratified limestone, rival-
ling the chalk of England in thickness. This Sicilian
ftiarl is older than the superincumbent limestone, but
aewer than the Subapennine marl of the north of Italy;
f °r in the latter the extinct shells rather predominate
°ver the recent, in the Sicilian strata the recent spe-
cks predominate almost to the exclusion of the extinct.
Subapennine marls. — I shall now consider more
Particularly the characters of those Subapennine beds
.^hich may be referred to the Older Pliocene period.
ne m ost important member of the Subapennine
mauon is a marl which varies in colour from grey-

S 1 br °wn to blue. It is very aluminous, and usually

contains much calcareous matter and scales of mica.

often exhibits no lines of division throughout a

considerable thickness, but in other places it is thinly

ai *nnated. Near Parma, for example, I have counted
thirty distinct laminae in the thickness of an inch. In
some of the hills near that city the marl attains,
a ccording to Signor Guidotti, a thickness of nearly

Wo thousand feet, and is charged throughout with
stle lls, many of which are such as inhabit a deep sea.

d 3

OLDER PLIOCENE PERIOD.

[Book IV.

They often occur in layers in such a manner as to
indicate their slow and gradual accumulation. They
are not flattened, but are filled with marl. Beds of

Medesano

four leagues from Parma; subordinate beds of gypsum
also occur in many places, as at Vigolano and Bar-
gone, in the territory of Parma, where they are inter-
stratified with shelly marl and sand. At Lezignano,
in the Monte Cerio, the sulphate of lime is found in
lenticular crystals, in which unaltered shells are some-
times included. Signor Guidotti, who showed me
specimens of this gypsum, remarked, that the sulphu-
ric acid must have been fully saturated with lime
when the shells were enveloped, so that it could not
act upon the shell. According to Brocchi, the marl
sometimes passes from a soft and pulverulent substance
into a compact limestone, but it is rarely found in
this solid form.* It is also occasionally interstratified
with sandstone.

The marl constitutes very frequently the surface of
the country, having no covering of sand. It is some-
times seen reposing immediately on the Apennine
limestone ; more rarely gravel intervenes, as in the
hills of San Quirico. + Volcanic rocks are here and
there superimposed, as at Radicofani, in Tusca. v ,
where a hill composed of marl, with some few shells
interspersed, is capped by basalt. Several of the
volcanic tuffs in the same place are so interstratified
with the marls as to show that the eruptions took
place in the sea during the Older Pliocene period. At
Acquapendente, Viterbo, and other places, hills of the
same formation are capped with trachytic lava, and

n y

* Conch. Foss. Subap., torn. i. p. 82

f Ibid., p. 78

Ch. XII.]

SUBAPENNINE YELLOW SAND

^ith tuffs which appear evidently to have been sub-

aqueous.

Yellow sand. — The other member of the Sub-
apennme group, the yellow sand and conglomerate,
constitutes, in most of the places where I have seen
it, a border formation near the junction of the tertiary
and secondary rocks. In some cases, as near the town
ot sienna, we see sand and calcareous gravel resting
immediately on the Apennine limestone, without the
intervention of any blue marl. Alternations are there
seen of beds containing fluviatile shells, with others
filled exclusively with marine species ; and I observed
oysters attached to many of the pebbles of limestone.
This appears to have been a point where a river, flow-
ing from the Apennines, entered the sea in which the
tertiary strata were formed.

-Between Florence and Poggibonsi, in Tuscany,
there is a great range of conglomerate of the Sub-
apennine beds, which is seen for eleven miles continu-
ously from Casciano to the south of Barberino. The
pebbl

re chiefly of whitish limestone, with some
sandstone. On receding from the older Apennine
rocKs, the conglomerate passes into yellow sand and
sandstone, with shells, the whole overlying blue marl.
-In such cases we may suppose the deltas of rivers and
torrents to have gained upon the bed of a sea where
b lue marl had previously been deposited.

-The upper arenaceous group above described some-
times passes into a calcareous sandstone, as at San
] gnone. It contains lapidified shells more frequently
than the marl, owing probably to the more free per-
flation of mineral waters, which often dissolve and
carry away the original component elements of fossil
bodies, and substitute others in their place. In some

d 4

:II, ;

OLDER PLIOCENE PERIOD.

[Book iy.

cases the shells imbedded in this group are silicifierf

as at San Vitale, near Parm* f i dre T S ed?

• v -a i t ^arma, from whence I saw two

individuals of recent species nn« f 1 ,

other marine /T Jm &pe " es ' one freshwater and the
othei marine (Limnea palustris, and Cytherea concen
tnca, Lamk.), both nprfiwi , c °«cen-

On the ni7i e f Cty ?™^ *• <**.

Mon t

The

Rome, which are probah.v refe rahl 7 Z Z'ZZ
at,on, are changed into calcareous spar> t he £ tail
preserved notw.thstanding ,he crystallization of hf

carbonate of lime.

Mafe o// oma ^ 0/ the Subapennine beds. - me
tertiary strata above described have resulted from the
waste of the secondary rocks which now form the
Apennines, and which had become dryland before the
Older Pliocene beds were deposited. In the territory
of Placentae have an opportunity of observing the
kind of sediment which the rivers are now brig Z
down from the Apennines. The tertiary marl of ^
district being too calcareous to be used for bricks Z
pottery a substitute is obtained by conveyin- into
tanks the turbid waters of the rivers Braganza, Parm a
Taro, and Enza In the course of a year a deposit of
brown clay, much resembling some of the Subapennine
marl is procured, several feet in thickness, divided
into thin laminse of different shades of colour.

In regard to the sand and gravel, we see yellow
sand thrown down by the Tiber near Rome, and by
the Arno, at Florence. The northern part of the

Apennines consists ^ o •

y consists of a grey micaceous sandstone

with an argillaceous base, alternating with shale fr om
the degradation of which brown clay and sand would
result. If a river flow through such strata, and some
one of its tributaries drains the ordinary limestone of
the Apennines, the clay might become marly by the

Ch - XII.] SUBAPENNINE STRATA, HOW FORMED

intermixture of calcareous matter. The sand is fre-
quently yellow from being stained by oxide of iron ;
but this colour is by no means constant.

The similarity in composition of the tertiary strata
in the basins of the Po, the Arno, and the Tiber, is
merely such as might be expected to arise from their
having been all derived from the disintegration of the
same continuous chain of secondary rocks. But it
does not follow that the latter rocks were all upheaved
and exposed to degradation at the same time. The
correspondence of the tertiary groups consists in their
being all alike composed of marl, clay, and sand ; but
we might say as much of the beds of the London and
Hampshire basins, although the English and Italian
groups, thus compared, belong nearly to the two
opposite extremes of the tertiary series.

The similarity in mineral character of the lacustrine
deposit of the Upper Val d'Arno, and the marine
Subapennine hills of northern Italy, ought to serve as
a caution to the geologist, not to infer too hastily a
contemporaneous origin from identity of mineral com-
position. The deposit of the Upper Val d'Arno oc-
curs nearly at the bottom of a deep narrow valley,
which is surrounded by precipitous rocks of secondary
sandstone and shale (the macigno of the Italians, and
greywacke of the Germans). Hills of yellow sand, of
considerable thickness, appear around the margin of
tll c small basin; while, towards the central parts,
where there has been considerable denudation, and
where the Arno flows, blue clay is seen underlying
the yellow sand. The shells are of freshwater origin,
but I shall speak more particularly of them when dis-
cussing the probable age of this formation in the six-
teenth chapter. I desire at present to call attention

d 5

OLDER PLIOCENE PERIOD.

[i>oolw TV

to the fact, that we have here, in an isolated basin,
such a formation as would result from the waste of the
contiguous secondary rocks of the Apennines, frag-
ments of which rocks are found in the sand and con-

glomerate. We

beds were removed, and the barrier of the lake-basin
closed up again, similar sediment would be again de-
posited; since the aqueous agents would operate in
the same manner, at whatever period they might be in
activity. Now, the only difference in mineral compo-
sition, between the lacustrine deposit and the ordinary
marine Subapennine strata, consists in the absence of
calcareous matter from the clay; and this may be
ascribed to the circumstance that the torrents flowing
into the lake had passed over no limestone rocks.

The lithological character of the Subapennine beds
varies in different parts of the Peninsula both in colour
and degree of solidity. The presence, also, or ab-
sence of lignite and gypsum, and the association or
non-association of volcanic rocks, are causes of great
local discrepancy. The superposition of the sand and
conglomerate to the marl, on the other hand
general point of agreement, although there ^e ex-
ceptions to the rule, as at San Quirico before men-
tioned. The cause of this arrangement may be, as I
before hinted, that the arenaceous groups were' first
formed on the coast where rivers entered ; and when
these pushed their deltas farther out, they threw
down the sand upon part of the bed of the sea already
occupied by finer and more transportable mud.

Captain Bayfield, in his Survey of the Coast of
St. Lawrence, mentions horizontal strata of sand and
gravel, and a subjacent deposit of clay, as reposing in
depressions in the older rocks near the shore. The

is a

I ^

CTN

- •

»S

fiq

t I

's.

*SJ

^ *.

»5 n

r ^

N| ^

St *

«c

TSJ

r s

^
M

-o

^ -S

>s*

'A £ i S |

* —

■

•

Ch.XH.] ORGANIC REMAINS OF SUBAPENNINES.

clay invariably occupies the lowest position, and the
gravel the highest; and this arrangement, he says,
may be explained by considering that the rivers where
they now bring down alluvial matter on several parts
of this coast, carry gravel over a bottom previously
occupied by clay, the finer sediment having first been
drifted farther from the shore.*

When Captain Bayfield proposed this theory, he had
*iot seen my work ; and it was satisfactory to observe

the exact coincidence of his views with my own,
his havin

g been suggested by the modern changes
going on in the St. Lawrence, mine by reasoning on
appearances in the interior of Italy.

Organic remains. — Figures of some of the most
abundant shells of the Subapennine formations are
given in the accompanying plate. (PI. X.) The greater
part of them are common both to the Older and Newer
Pliocene periods of this work. Eight of the species,
Nos - 1> 3, 5, 6, 7, 9, 13, and 14, are now living, but
are also common in the older Pliocene formations,
-rusus crispus has not been found either recent, or in
the Miocene or Eocene formations,, but occurs both in
the Older and Newer Pliocene formations. Mitra
phcatula has been observed only in the Older Pliocene
deposits. The Turbo rugosus was formerly considered
^ s exclusively Pliocene; but M. Boue has since found
1 ln the Miocene strata at Vienna and Moravia. Buc-
Clnum semistriatum is also a Miocene shell, but has

been inserted

Pli

as being peculiarly abundant in the

iocene strata.

The Subapennine testacea are referable to species

An abstract of this paper will be found in the Proceedings

oftheGeol. Soc, No. 33. p. 4.

D 6

OLDER PLIOCENE PERIOD

[Book IV.

and families of which the habits are extremely diver-
sified, some living in deep, others in shallow water,
some in rivers or at their mouths. I have seen a
specimen of a freshwater univalve (Limnea palustris),
taken from the blue marl near Parma, full of small
marine shells. It may have been floated down by the
same causes which carried wood and leaves into the
ancient sea.

I have been informed, by experienced collectors of
the Subapennine fossils, that they invariably procure
the greatest number in those winters when the rains
are most abundant ; an annual crop, as it were, being
washed out of the soil to replace those which the
action of moisture, frost, and the rays of the sun soon
reduce to dust upon the surface.

The shells, in general, are soft when first taken from
the marl, but they become hard when dried. The
superficial enamel is often well preserved, and many
shells retain their pearly lustre, and part of their ex
ternal colour, and even the ligament which unites the
valves. No shells are more usually perfect than the
microscopic, which abound near Sienna, where more
than a thouand full-grown individuals are sometimes
poured out of the interior of a single univalve of mo
derate dimensions. In some large tracts of yellow
sand it is impossible to detect a single fossil, while in
other places they occur in profusion.

Blocks of Apennine limestone are found in this
formation drilled by lithodomous shells. The remains
not only of testacea and corals, but of fishes and crabs,
are met with, as also those of cetacea, and even of
terrestrial quadrupeds.

A considerable list of the mammiferous species has
been given by Brocchi and some other writers ; and

h.XIL] STRATA AT BASE OF MARITIME ALPS. 61

although several mistakes have been made, and some
bones of cetacea have been confounded with those of
land animals, it is still indubitable that some remains of
land animals were carried down into the sea when the
kubapennine sand and marl were accumulated. The
same causes which drifted skeletons into lakes, such as
that of the Upper Val d'Arno, may have carried down
others into firths or bays of the sea. The femur of an
elephant has been disinterred with oysters attached to
it, showing that it remained for some time exposed
after it was drifted into the sea.

of the Maritime

If we pass

from the Italian peninsula, and, following the borders

Med

the foot bf the Maritime Alps, we find formations
agreeing in zoological characters with the Subapennine
beds, and presenting many points of analogy in their
mineral composition. The Alps, it is well known, ter-
minate abruptly in the sea, between Genoa and Nice,
and the steep declivities of that bold coast are con-
tinued below the waters ; so that a depth of many
Hundred fathoms is often found within stone's-throw of
the beach. Exceptions occur only where streams and
torrents enter the sea ; and at these points there is
always a low level tract, intervening between the
mouth of the stream and the precipitous escarpment
°f the mountains.

In travelling from France to Genoa, by the new
coast road, we are conveyed principally along a ledge
excavated out of a steep slope or precipice, in the
same manner as on the roads which traverse the great
interior passes of the Alps, such as the Simplon and
■Mont Cenis ; the difference being that, in this case, the
traveller has always the sea below him, instead of a

^mm^^^^^^^

OLDER PLIOCENE PERIOD

[Book IV.

river. But we are obliged occasionally to descend by
a zigzag course into those low plains before alluded to,
which, when viewed from above, have the appearance
of bays deserted by the sea. They are surrounded on
three sides by rocky eminences, and the fourth is open
to the sea.

These leading features in the physical geography of
the country are intimately connected with its geological
structure. The rocks composing the Alpine declivities
belong partly to the primary formations, but more
generally to the secondary, and have undergone im-
mense disturbance ; but when we examine the low
tracts before mentioned, we find the surface covered
with great beds of gravel and sand, such as are now
nnually brought down by torrents and streams in the

• 1 1 • "1

winter, and which are spread in such quantity over the
wide and shifting river-channels as to render the roads
for a season impassable. The first idea which naturally
suggests itself, on viewing these plains, is to imagine
them to be deltas or spaces converted into land by the
accumulated sand and gravel brought down from the
Alps by rivers. But, on closer inspection we find that
the apparent lowness of the plains, which at first glance
might be supposed to be only just raised above the
level of the sea, is a deception produced by contrast.
The Alps rise suddenly to the height of several thou-
sand feet with a bold and precipitous outline ; while
the country below is composed of horizontal strata,
which have either, a flat or gently undulating surface!
The strata consist of gravel, sand, and marl, filled
with marine shells, and they are considerably elevated
attaining sometimes the height of two hundred feet
or even more, above the level of the sea ; there must
therefore, have been a rise of the coast since they were

Ch. XII.]

TERTIARY STRATA AT GENOA.

deposited, and they are not mere deltas or spaces re-
claimed from the sea by rivers. Why, then, are such
strata found only at the points where rivers enter?

We must imagine that, after the coast had nearly
acquired its present configuration, the streams which
flowed down into the Mediterranean produced shoals
opposite their mouths by the continual drifting in of
gravel, sand, and mud. " The Alps have since been
raised to a sufficient height to cause these shoals to
become land ; while the corresponding elevation of the
intervening parts of the coast, where the sea was of
great depth near the shore, has not been perceptible.

The disturbing force appears to have acted very
irregularly, and to have produced the least elevation
towards the eastern extremity of the Maritime Alps,
and a greater amount as we proceed westward. Thus
w e find the marine tertiary strata attaining the height
°f about 100 feet at Genoa, 200 and 300 feet farther
westward at Albenga, and 800 or 900 feet in the
nei ghbourhood of Nice.

At Genoa the tertiary strata consist of

Monte

d'Origina

Fig. 116.

///A

Sea

«.

Position of tertiary strata at Genoa.

Ancient sea-beach.

b. Blue marl with shells

C. Inclined secondary strata of sandstone, shale, &c.

OLDER PLIOCENE PERIOD.

[Book IV.

blue marls like those of the northern Subapennines
and contain the same shells. On the immediate site
of the town they rise to the height of only twenty feet
above the sea ; but they reach about eighty feet in
some parts of the suburbs. At the base of a moun-
tain not far from the suburbs there is an ancient beach,
strewed with rounded blocks of Alpine rocks, some of
which are drilled by the Modiola lithophaga, Lamk.,
the whole cemented into a conglomerate, which
marks the ancient sea-beach at the height of 100 feet
above the present sea, *

Savona. — At Savona, proceeding westwards, we
find deposits of blue marl like those of Genoa, and
occupying a corresponding geological position at the
base of the mountains near the sea. The shells, col-
lected from these marls by Mr. Murchison and myself,
in 1828, were examined by Signor Bonelli, of Turin,
and found to agree with Subapennine fossils.

Albenga. — At Albenga these formations occupy a
more extensive tract, forming the plains around that
town and the low hills of the neighbourhood, which
reach in some spots an elevation of 300 feet. The
encircling mountains recalled to my mind those which
bound the plain and bay of Palermo, and other bays
of the Mediterranean, which are surrounded by bold
rocky coasts.

The general resemblance of the Albenga strata to
the Subapennine beds is very striking ; the lowest
division consisting of blue marl which is covered by
sand and yellow clay, and the highest by a mass of
stratified shingle, sometimes consolidated into a con-

* I have here to acknowledge my obligations to Professor
Viviani, and Dr. Sasso, who called my attention to these phe-
nomena when I visited Genoa in Jan. 1829.

Ch. XII.]

TERTIARY STRATA AT NICE.

glomerate. Dr. Sasso has collected about 200 species
of shells from these beds ; and it appears, by his cata-
logue, that they agree, for the most part, with the
northern Subapennine fossils, more than half of them
belonging to recent species. *

-(.vice. ■ — At Nice the tertiary strata are upraised to
a much greater height, but they may still be said to
he at the base of the Alps which tower above them.
■Were, also, they consist principally of blue marl and
yellow sand, which appear to have been deposited in
submarine valleys previously existing in the inclined
secondary strata. In one district, a few miles to the
West of Nice, the tertiary beds are almost exclusively

■

composed of conglomerate, from the point of their
junction with the secondary strata to the sea.

The river Magnan flows in a deep valley, which ter-
minates at its upper extremity in a narrow ravine,
early vertical precipices are laid open on each side,
varying from 200 to 600 feet in height, and composed
inclined beds of shingle, sometimes separated by
a yers of sand, and more rarely by blue micaceous

The pebbles in these stratified shingles agree

m composition with those now brought down from the

ps by the Var and other rivers on this coast.

-•-he dip of these strata is remarkably uniform, being

always southwards, or towards the Mediterranean, at

an an g!e of about 25°. I examined this section in

company with Mr. Murchison in the summer of 1828,

hen the bed of the river was dried up. The geolo-

b J st has then a good opportunity of examining a sec-

1Q n of the strata, as the channel crosses for many

mi les the line of bearing of the beds, which may be

marl.

■

* Giornale Ligustico, Genoa, 1827

OLDER PLIOCENE F^RIOxJ.

[Book IV.

Monte

Med

It is usually impossible to determine the exact age of
such accumulations of sand and gravel, in consequence
of the total absence of organic remains- Their non-
existence may depend chiefly on the disturbed state of
the waters, where great beds of shingle are formed,
which are known to prevent testacea and fishes from
living in Alpine torrents ; partly on the total destruction
of shells by the same friction which rounded the peb-
bles ; and partly on the permeability of the matrix to
water, which may carry away the elements of the de-
composing fossil body, without substituting any other
substance in their place which might retain a cast of

their form.

But it fortunately happens, in this instance, that in
some few seams of loamy marl, intervening between
the pebble-beds, and near the middle of the section,
shells have been preserved in a very perfect state •
and these may furnish a zoological date to the whole
mass. The principal of these interstratified masses of
loam occurs near the church of St. Madeleine (at c,
diagram No. 117.)? where the active researches of M.
Eisso have brought to light a great number of shells
which agree perfectly with the species found in much
greater abundance at a spot called La Trinita, and
some other places nearer Nice. From these fossils it
clearly appears that the formation belongs to the Older
Pliocene era.

with the usual thin

Such alternations of gravel

layers of fine sediment may easily be explained, if we
reflect that the rivers now flowing from the Maritime
Alps are nearly dried up in summer, and have only
strength to drift along fine mud to the sea ; whereas

c h. XII.]

TERTIARY STRATA AT NICE.

m winter, or on the melting of the snow, they roll
along large quantities of pebbles. The thicker masses
of loam, such as that of St. Madeleine, may have been
produced during a longer interval, when the river
shifted for a time the direction of its principal channel
of discharge ; so that nothing but fine mud was for a
series of years conveyed to that point in the bed of
the sea opposite the delta.

Monte Calvo.

Fig. 117.

/ /
/

Section from Monte Calvo to the sea by the valley of Magnan, near Nice,

A » dolomite and sandstone- (Green-sand formation ?)

a 9 v, d. Beds of gravel and sand.

c - Fme marl and sand of St. Madeleine.

lform ar,( * continuous as the strata appear, on a

. era * V1 ew, in the ravine of the Magnan, we discover,

e a ttempt to trace any one of them for some dis-

n ce, that they thin out and are wedge-shaped. We

ev e that they were thrown down originally upon a

e p slanting bank or talus, which advanced gradually

The dis-

nce between these points is, as before mentioned,
f out nine miles ; so that the accumulation of super-
posed strata would be a great many miles in thick-

ess > if they were placed horizontally upon one another-

OLDER PLIOCENE PERIOD.

rest to Monte f!aW *hi

[Book IV.

pressed by a, are certainly older than those at b, and
the group b was formed before c. The aggregate thick-
ness, in any one place, cannot be proved to amount to
1000 feet, although it may, perhaps, be much greater.
But it may never exceed 3000 or 4000 feet ; whereas,
it we did not suppose that the beds were originally
deposited m an inclined position, we should be forced
to imagine that a sea, many miles in depth, had been
filled up by horizontal strata of pebbles thrown down
one upon another.

At no great distance on this coast the Var is an-
nually seen to sweep down into the sea a large quan-
tity of gravel, which may be spread out by the waves
and currents over a considerable space. The sea at
the mouth of this river is now shallow, but it may
originally have been 3000 feet deep, as it is now close
to the shore at Nice. Here, therefore, a formation

be in progress.

In confirmation of the above reasoning, I may refer
to the modern delta of the river Kander in the lake
of Thun in Switzerland. The Kander formerly ran
Parallel to that lake, until it was artificially turned
into it about the year 1713, when the government of
Berne caused two parallel subterranean galleries or
tunnels to be excavated through the land which separ-

ated the course. of the river from *h* i~i r <.

c i ., m rrom «ie-Iake ; a distance

of nearly a mile The Kander, on being admitted,
shot with the violence of a Swiss torrent through the
tunnels, burst the arches of the galleries, and formed
a ravine, which is now open to the day, about fifty
feet in depth. A large quantity of mud and rock was
swept into the lake, and an alluvial tract was formed

Ch.XlL]

TERTIARY STRATA OF THE PYRENEES.

ot a semicircular shape, which now extends for a mile

a °ng the original shore, and projects about a quarter

that distance into the lake. Its annual advance is

said to amount to several yards*, and the delta ter-

mates in a talus, the slope of which is inclined at

angles varying between 15° and 25°. Such was

result of my own observations, in 1836, when I

funded the lake opposite the mouth of the Kander.

e greatest inclination which I found gave an angle

of 2 9 , the least 6°.f It follows, therefore, that the

ata have successively accumulated on a plane thus

. x g% inclined ; so that, if the Lake of Thun, which

s 600 feet deep J, beyond the recently formed shoal,

er e drained, a vertical section might be laid open,

u feet in height, in which strata would be seen

alth

ough

)se of the Magnan,
they had remained undisturbed from the

" ri od of their original deposition.

rtiary Strata at the eastern extremity of

yrenees.

I shall conclude this chapter with one

extremi

ore example, derived from a region not far distant.

the borders of the Mediterranean, at the eastern

*ty of the Pyrenees, in the south of France, a

S1 derable thickness of tertiary strata is seen in the

valleys of the rivers Tech, Tet, and Gly. They bear

. c h resemblance to those already described, consist-

S partly of a large proportion of conglomerate, and

^ev. j. Yates, on Alluvium, Edin. New Phil. Journ. 1834.

18 d C ° le and the Rev * Mr# E 8 erton measured the dip in

3 > and concluded that it was still more considerable (Pro-

ng s of Geol .Soc. 1834.) ; but they tell me that they had not

"* time or implements to insure accuracy in their sound-

* Mr. Yates, ibid.

■ I

: 1

: U

OLDER PLIOCENE PERIOD.

[Book IV.

partly of clay and sand, with subordinate beds of
lignite. They abut against the primary formation of
the Pyrenees, which here consists of mica-schist.
Between Ceret and Boulon these tertiary strata are
seen inclined at an angle of between 20° and 30
The shells which I procured from several localities

Subapennine fossils.

Spain

Morea

It appears, from the recent ob-

servations of Colonel Silvertop, that marine strata of

Malaga

and in Granada in Spain. They have also been dis-
covered by MM. Boblave and Virlet in the Morea.

CHAPTER XIII.

OLDER PLIOCENE FORMATIONS

CRAG.

an d red cra<r.

■

a S of Norfolk and Suffolk — Appears by its fossil contents to
«*tong to the Older Pliocene period. - Divisible into coralline

Superincumbent deposits — Forms of stratifi.

^tion (p. 78.) — Oblique layers— Cause of this arrangement—

u 'slocations in the strata produced by subterranean movements

overlaying the shelly crag— P/otruded masses of chalk (p. 85.)

Similar appearances in the cliffs of Mb'en in Denmark.

he Older Pliocene strata, described in the last chap-
ter, are all situated in countries bordering the Medi-
terranean ; but there is a group in our own island,
Probably belonging to the same era, which I shall now
consider. I have already alluded to this deposit under

e provincial name of crag *, and pointed out its
s uperposition to the London clay, a tertiary formation
of much higher antiquity, f The crag is chiefly de-
veloped in the eastern parts of Norfolk and Suffolk,
* r om whence it extends into Essex.

Its relative age. — A collection of the shells of the

- crag" beds, which I formed in 1829, together with

jjmuch larger number sent me by my friend Mr.

fantell, of Brighton, were carefully examined by M.

eshayes, and compared with the tertiary sDecies in
hscabi ' -

met. Moi

y him to be of extinct species, not agreeing in general

Mioc

ne remainder were of recent species, and considered

* Vol. in. p . 336>

+ See Fig. 84. Vol. III. p. 338,

OLDER PLIOCENE PERIOD.

[Book IV.

to be identical with testacea now living in the German

Ocean. For these reasons it was inferred that the
crag was older than the Miocene period, and about as
far removed in conchological character from the shells
of our seas, as are the Subapennine strata from the

Out of 111

species examined in Paris in 1829, sixty-six were re-
garded as extinct, and forty-five as recent*; and when
I lately submitted to the inspection of M. Deshayes
sixty other species, procured from the lowest or coral-
line crag, he still retained the same opinion in regard
to the proportion of recent species. A larger number,

however, of organic remains has of late years been
obtained from the crag, principally by Mr. Wood of
Hasketon, in Suffolk, who states that he has in his col-
lection, exclusive of Polypi, Radiaria, and Crustacea,
no less than 450 species of invertebrated animals from
the crag, among which there are of annulata 13, cirrhi-
peda 11, conchifera 189, mollusca 257.

But these fossils have not yet been examined with
sufficient attention to enable me to say, whether the
results to which they lead should modify the conclu-
sions previously deduced from more limited data.f

* M. Deshayes is now aware that he. was mistaken in supposing
one of these crag fossils, Valuta Lamberti, to be identical with a
recent species.

•f Dr. Beck, of Copenhagen, well known for his profound
knowledge of recent shells, has lately seen 260 species of cra«*
shells in Mr. Charles worth's cabinet in London, and informs me,
that although a large proportion of the species approach very
near to others which now live in our northern seas, he regards
them as almost all of distinct species, and not recent. I attribute
this discordance of opinion between the Danish naturalist and
M. Deshayes, chiefly to the different estimate which they have
formed of the amount of variation necessary to constitute a dis-

Ch. XIII.]

CRAG OF ENGLAND.

that the crag may be divided into two distinct masses,
one of which may be termed the lower or " coralline
Q ™?\ and the other the " red crag." The lower
ivision is composed of calcareous sand, chiefly derived
rom decomposed corals, in which are imbedded shells,
corals, and sponges, in a good state of preservation,
a nd which must evidently have lived on the spot.

This coralline formation is often without distinct
stratification, and in some places forms a soft stone
Used in building : it is said to attain a thickness of
^ore than 50 feet at Orford, and was not pierced
through even at that depth. The coralline crag rests
^mediately on the London clay, and may be studied
at several places in Suffolk, as at Tattingstone, Rams-
holt, Sudburn Park, Orford, and Aldborough.

The red crag is distinguished from the coralline,
upon which it lies in some places unconformably, by
the deep red ferruginous or ochreous colour of its sands
an d fossils. It consists in great part of numerous
la yers of siliceous sand containing shells, which are
Usually broken and worn. Among these are many of

Un ct species. It seems natural that those who, like M. Deshayes,

ay e been long engaged in the study of fossils, should acquire a

ore enlarged conception of the modifications which time and

r cumstances may produce in species, even though they reject

e Lamarckian doctrine of transmutation. This subject, how-

er y requires a thorough re-examination, as respects the crag

°ssils. Mr. Milne Edwards tells me that he has seen a small

rnber of corals or polypifera from the crag, none of which are,

ln bis opinion, recent. On the other hand, Dr. Fleming, as I

Mentioned in a former edition, considers the Eschara retiformis,

and several other zoophytes of this formation, as perfectly identical

Wlth livin g species. Both M. Deshayes and Dr. Beck agree in.

pronouncing the crag shells to be those of a northern climate.

VOL. iv.

;

OLDER PLIOCENE PERIOD,

[Book IV.

the genera Buccinum and Fusus^ which have never
been met with in the coralline crag.

Some have imagined the

red crag

to consist in

great measure of transported materials derived from
the breaking up of the coralline crag ; but I can fully
confirm the observation of Mr. R. E. Taylor and others,
that this deposit has been gradually formed, as may be
inferred from stratification, and from the fact of certain
shells occurring at intervals in groups and genera, and
being by no means diffused everywhere, nor scat-
tered at random, through the beds.

Another question has also arisen respecting the
coralline and the red crag, namely, whether both of
them belong to the same tertiary period. Of the
fossil shells in Mr. Wood's collection, 235 species are
said to have been procured from the red crag, and 353
from the coralline beds, and out of these 150 species
are common to the two divisions. Mr. Charlesworth
suggests that, even of these 150 species, many may
have belonged originally to the lower bed, and have
been washed into the newer one, in the same manner
as some fossil shells of the chalk have certainly been
imbedded in the crag, and as crag shells are now daily
washed into the sea on our coast, and mixed with re-
cent shells. But, although such accidental mixtures
have doubtless occurred, I see no sufficient reason at
present for believing that the two divisions of the crag
should be referred to distinct tertiary periods. It is
not disputed that many fossils are truly common to
both divisions of the crag, and equally abundant in
each. The remarkable want of correspondence in
the genera of shells, and even in some other classes
and families of organic remains, characteristic of each
division, affords by no means a strong argument in

**-*•- ***

Ch. XIII.]

fav

CRAG OF ENGLAND.

our of a wide difference in epoch. It is said that

here are few indications of fish in the coralline crag ;

Whereas in the red crag, the teeth and bones of fish of

the genera Carcharias, Myliobates, Galeus, Lamna,

^oudanus, an d Pl ata x, are found abundantly. So also

th 1S / emarked that mammalian remains, as those of
^ e -Elephant, Horse, and others, are chiefly confined

the upper or red crag, whereas corallines and other
*°°phy tes, as also microscopic foraminifera (of which

«. Wood has obtained fifty species), belong almost
delusively to the lower or coralline division. *

Now these distinctions are precisely of a kind which
^°uld depend on differences of a local rather than a
chronological nature. Thus in one part of the sea
may suppose a region, where the water is deep
an d tranquil, to be favourable to the growth of corals,
s P°nges, echini and microscopic cephalopods, such as
characterize the lower crag ; whilst in another and
0r »ewhat shallower region, where currents prevailed,
and to which sand and shingle were often drifted, no'
z °ophytes might exist, although certain kinds of tes-
a ?ea abounded. According to this hypothesis, a cer-
a j« space where the coralline crag was first formed
^ !§ht afterwards have been converted into a shallower
J ea > or exposed to the action of waves and currents,

o as to become the receptacle of deposits like the red
crag.

T, •

is only when we can compare fossils of the same

wkhVt SheHS Wlth ShellS ' C ° rals With Corals ' and fish

th ' and When We find that a lai *g e proportion of

e species thus compared are dissimilar, that we can

E 6r two § rou Ps of strata to different periods.

•*

Charlesworth, Phil. Mag., June, 1836, vol. viii. p. 535.

E 2

.ft

™

OLDER PLIOCENE PERIOD.

[Book IV,

There may nevertheless have been a long interval
of time, and some amount of change in the marine
fauna, between the times of the deposition of the lower
and upper crag ; for when we adopt only four tertiary
periods, as proposed in this work, the number of ages
probably comprised in any one of them, as for instance
in the Older Pliocene, may be indefinitely great.

The shelly beds of Norfolk appear to belong exclu-
sively to the red crag ; but on the northern limits of
that county they are said to be occasionally covered
by a still newer stratum, containing exclusively species
now living in the adjoining sea. This is doubtless the
marine formation described by Mr. Phillips as occur-
ing throughout Holderness, in Yorkshire. # Accord-
ing to this view, the succession of tertiary formations,
in following our eastern coast from the estuary of
the Thames to that of the Humber, will be, first, in
Essex, the Eocene or London clay ; secondly, in
Suffolk, the coralline crag, probably belonging to the
Older Pliocene period ; next, the red crag of Suffolk
and Norfolk, also of the same era ; and lastly, on the
extreme northern boundary of Norfolk and in Holder-
ness, a marine Newer Pliocene deposit.

Superimposed upon the fossiliferous crag in the
cliffs of Norfolk and Suffolk, is a formation of much
greater thickness, and of more uncertain age. It has
been sometimes classed with the crag and sometimes
distinguished from it under the name of diluvium. A
large portion of it is regularly stratified, but other
parts consist of a confused heap of mud and rubbish

frag-

entirely without stratification, and containing

ments of various rocks, some derived from the oolitic

* See Phillips's Geol. of Yorksh.

Ch. XIII.]

CRAG OF ENGLAND.

series with their characteristic fossils, others from the
chalk and London clay, together with granitic and
other pebbles transported from a great distance. In
some places this formation consists of sand and shingle
ln a *ternate beds destitute of organic remains, and
of considerable thickness, as in the Suffolk cliffs be-
tween Dunwich and Yarmouth. Elsewhere it is com-
posed of blue or brown marl, sand, loam, and clay, con-
taining bones of terrestrial quadrupeds with drift wood
ar *d beds of lignite.

Above this deposit of uncertain age, are occasional
patches of lacustrine strata, filling up small cavities
w hich must have once been lakes or ponds on the sur-
face of the country, and in which strata of loam and peat

■

accumulated, including recent freshwater testacea.
The annexed section may give a general idea of

Fig.

118.

a * Chalk, b. Shelly crag and overlying strata of uncertain age.
c Lacustrine deposit (newer pliocene).

C Trimmingham beacon.

E. Interior and higher part of Norfolk.*

the manner in which the crag and the superimposed
gravel, sand, and marl rest on the chalk as we pass from
the Norfolk cliffs, at Trimmingham, into the interior,
where the country rises gradually.

The outline of the surface of the subjacent chalk,
m this section, is imaginary, but is such as might ex-

This section is compiled principally from one by Mr. Mur-
chison; the others in this chapter are from sketches which I
made in 1829.

E 3

* 'f*

■

OLDER PLIOCENE PERIOD.

[Book IV.

plain the relations of those protruded masses of chalk,
three of which appear in the cliffs near Trimmingham,
and which some geologists have too hastily assumed to
be unconnected with the great mass of chalk below.
I shall treat of these presently, when describing the
disturbances which the tertiary strata of the Norfolk
cliffs have suffered since their original deposition.

In the interior, at e, there is a thick covering of
sand and gravel upon the chalk, having the characters
of an alluvium, but which seems to pass gradually into
the regular strata of sand, shingle, and loam before
described as covering the shelly crag.

Forms of stratification. — In almost every formation
the individual strata are rarely persistent for a great
distance, the superior and inferior planes being seldom
precisely parallel to each other; and if the materials
are very coarse, the beds often thin out if we trace
them for a few hundred yards. There are also many
cases where all the layers are oblique to the general
direction of the strata, and the crag affords most in-
teresting illustrations of this phenomenon.

Walton

Martello

* * vj^iwoV/UtCU 111

the annexed diagram is seen. The vertical height is
about twenty feet, and the beds of crag consist alter-
nately of sets of inclined and horizontal layers of sand

Fig. 1 1 9.

Section of shelly crag near Walton, Suffolk.

Ch. XIII.]

CRAG OF ENGLAND,

and comminuted shells. The sand is siliceous, and of
a ferruginous colour ; but the layers are sometimes
made up of small plates of bivalve shells, arranged with
their flat sides parallel to the plane of each layer, like
mica in micaceous sandstones.

The number of laminae in the thickness of an inch,
both in the siliceous and shelly sand, varies from
seven to ten, so that it is impossible to express them
all in the diagram. The height of the uppermost

stratum is, in this instance, remarkable, as it extends
to twelve feet. The inclination of the laminae is about
30° ; but in the cliffs of Bawdesey, to the eastward,
they are sometimes inclined at an angle of 45°, and

e ven more.

Fig. 120.

Section at the lighthouse near Happisborough. Height sixteen feet.

a. Pebbles of chalk flint, and of rolled pieces of white chalk

6. Loam overlying a.

c, c. Blue and brown clay.

This diagonal arrangement of the layers, sometimes
called "false stratification," is not confined to deposits
°f fine sand and comminuted shells ; for we find beds
°f shingle disposed in the same manner, as is seen in
the annexed section (Fig. 120.).

The direction of the dip of the inclined layers,
throughout the Suffolk coast, is so uniformly to the
south, that I only saw two or three instances of a con-
trary nature, where the inclination was northerly. One
of the best examples of this variation is exhibited
in a cliff between Mismer and Dunwich (Fig. 121.).

E 4

■■■

OLDER PLIOCENE PERIOD.

1 [Book IV.

In this case, there are about six layers in the thick-
ness of an inch, and the part of the cliff represented is
about six feet high.

Fig. 121.

Section of part %^.^ f ^co mp ose d of quartzose sand, shoving the

inclination of the layers in opposite directions.

Another example may be seen near Walton, where
the layers, which are of extreme tenuity, consist of
ferruginous sand, brown loam, and comminuted shells.
It is not uncommon to find in this manner sets of per-
fectly horizontal strata resting upon and covered by
groups of wavy and transverse layers.

Fig. 122.

Lamination of ^SlSCff^ «*»

The appearances exhibited in the diagrams are not
peculiar to the crag : they may be found in almost
every gravel-pit; and I have seen sand and pebble-
beds of all ages, including the old red sandstone, grey-
wacke, and clay-slate, exhibit the same arrangement

If we now inquire into the causes of such a disposi-
tion of the materials of each bed or group of layers it
may, in the first place, be remarked, that, however

Ch.XlII.]

CRAG OF ENGLAND.

Fig. 123.

numerous may be the succes-
sive layers a, b> c, the layer a f
must have been deposited be-
fore 6, b before c, and so of the
rest.

down on a slope, and that it conformed itself to the
Sl de of the steep bank, just as we see the materials of
a talus arrange themselves at the foot of a cliff when
they have been cast down successively from above. If
the transverse layers are cut off by a nearly horizontal
l^e, as in many of the above sections, it may arise
from the denuding action of a wave which has carried
away the upper portion of a submarine bank, and
tr uncated the layers of which it was composed. But I
do not conceive this hypothesis to be necessary ; for
*f a bank have a steep side, it may grow by the suc-
cessive apposition of thin strata thrown down upon its
slanting side, and the removal of matter from the top
*flay proceed simultaneously with its lateral extension.
The same current may borrow from the top what it
gives to the sides ; a mode of formation which I had
lately an opportunty of observing on the rippled sur-
face of the hills of blown sand near Calais. The undu-
lating ridges and intervening furrows on the dunes of
blown sand resembled exactly in form those caused by
the waves on a sea-beach, and were always at right
a ^gles to the direction of the wind which had produced
them. Each ridge had one side slightly inclined, and

Fig. 124.

the other steep ; the lee side being always steep, as

e 5

ij I

OLDER PLIOCENE PERIOD.

[Book IV.

be d, e ; the windward side a gentle slope, as «, b, c, d

WhPTi a crust: nt winrl Kl^«r «.:xi. ™ . _ 7

- — oumuieiit rorce to drive

along a cloud of sand, all the ridges were seen to be
m motion at once each encroaching on the furrow

thtTla ce" K K ^ T^ ° f * ** «*> ^g
the place which the furrows had occupied. Many

fnrt "T drift6d *«* the 4h» « b and
« * which, when they fell over the scarps * e and d e

were under shelter from the wind; so that they rl
mained stationary, resting, according to their shape
and momentum, on different parts of the descent, in
this manner each ridge was distinctly seen to move
shwly on as often as the force of the wind augmented.
* e shall not strain analogy too far, by supposing that,
m such cases, the same laws may govern subaqueou
and subaenal phenomena ; and if so , We may im •
a submarine bank to be nothing more than „

ridges of ripple on a larger scale, which may increase

in the manner before suggested, by successive addition!
to the steep scarps. unions

The set of tides and currents, in opposite directions

7ir°z r s en variations in the ^

he dip of the layers, as represented in Fig. 1 24 . , wh il e
the general prevalence of a «nn*fc a i • , *''. wmie
the crag of Suffolk may hl£%*J* mU ' ™
brought by a current from £%£* *" ^ ™

I may refer ,o a drawing given in fte fet
to show the analogy of the arrangement rf £™ >>_
manne s rata Just considered, ,„ that exhibited by
deposits formed in the channels of rivers where a con
siderable transportation of sediment is in progress.

™™» „ „,_..,.. In the a[)OTe examples I

Derangement of

* P 378. Fig, 13.

riA

Ch. XIIL]

DERANGEMENT OF STRATA.

have explained the want of parallelism or horizon-
tally in the subordinate layers of different strata, by
reference to the mode of their original deposition ;
but there are signs of disturbance which can only be
accounted for by subsequent movements. The same
blue and brown clay, or loam, which is often perfectly
horizontal, and as regularly bedded as any of our older
formations, is, in other places, curved and even folded

back upon itself, in the manner represented in the an-
nexed diagrams.

Fig. 125.

Fig. 126.

Bent strata of loam in the cliffs
between Cromer and Runton.

Folding of the strata between East and

West Runton.

In the last of these cuts a central nucleus of sand
is surrounded by argillaceous and sandy layers. This
phenomenon is very frequent ; and there are instances
where the materials thus enveloped consist of broken
flints mingled with pieces of chalk, forming a white
mass, encircled by dark laminated clay. The diameter
of these included masses, as seen in sections laid open
in the sea cliffs, varies from five to fifteen feet.

East of Sherringham, a heap of partially-rounded
flints, about five feet in diameter, is nearly enveloped
by finely laminated strata of sand and loam, and some
of the loam is entangled in the midst of the flints.

In this and similar instances, we may imagine the

e 6

III

■

1 1

OLDER PLIOCENE PERIOD

[Book IV.

Fig. 127

Section in the Cliffs east of Sherringham.

a. Sand and loam in thin layers.

yielding strata, a, to have subsided into a cavity, and
the flints belonging to a superincumbent bed to have
pressed down with their weight, so as to cause the
strata to fold round them.

That some masses of stratified sand and loam have
actually sunk down into cavities, or have fallen like
landslips into ravines, seems indicated by other appear-
ances. Thus near Sherringham, the argillaceous beds,

(Fig. 128.)

. & , , , & iaui v xi g* izo.i, are

cut off abruptly and succeeded by the vertical and

contorted series b, c. The face of the cliff here repre-

Fig. 128.

Section east of Sherringham, Norfolk.

a. Sand, loam, and blue clay.
c. Twisted beds of loam.

h b. Sand and gravel

sented is twenty-four feet in height. Some of the lay-
ersin bb, are composed of pebbles, and these alternate
with thin beds of loose sand. The whole set must
once have been horizontal, and must have moved in a
mass, or the relative position of the several parts would
not have been preserved. Similar appearances may,

■ 1 ■

Ch. XIII.]

PROTRUDED MASSES OF CHALK.

perhaps, be produced when chasms open during earth-
quakes, and portions of yielding strata fall in from
above and are engulphed.

Protruded masses of chalk. — But whatever opinion
w e may entertain on this point, we cannot doubt that
subterranean movements have given rise to some of
*he local derangements of this formation, particularly
Where masses of solid chalk pierce, as it were, through

Fig. 129.

mde view of a promontory of chalk and tertiary strata, Trzmmingham, Norfolk*

Gravel and ferruginous sand, rounded and angular pieces of
chalk flint, with some quartz pebbles, 3 feet.

6 * Laminated blue clay, 8 feet.

c * Yellow sand, 1 foot, 6 inches.

**• Dark blue clay, with fragments of marine shells, 6 feet.

Yellow loam and flint gravel, 3 feet.

f m Light blue clay, 1 foot.

g. Sand and loam, 12 feet.

"• Yellow and white sand, loam, and gravel, about 100 feet.

the tertiary strata. Thus, between Mundesley and
-Inmmingham we see the appearances exhibited in the
accompanying view (Fig. 129.). The chalk, of which
the strata are highly inclined, or vertical, projects in a

i ■

OLDER PLIOCENE PERIOD.

[Book IV.

promontory, because it offers more resistance to the
action of the waves than the tertiary beds which, on
both sides, constitute the whole of the cliff The
height of the soft strata immediately above the chalk
is, in this place, about 130 feet. Those which are in
contact (see the wood-cut) are inclined at an angle of
45 , and appear more disturbed than in other parts of
the cliffs, as if they had been displaced by the move-
ment by which the chalk was protruded.

Very similar appearances are exhibited by the
northernmost of the three protuberances of chalk, of
which a front view is given in the annexed diagram.

Fig. 130

Northern protuberance of chalk, Trtmmtagkam

a. Chalk with flints.

b. Gravel of broken and half-rounded flints.

c. Laminated blue clav.

d. Sand and yellow loam.

It occupies a space of about one hundred yards alone
the shore, and projects about sixty yards in advance of
the general line of cliff. One of its edges, at c, rests
upon the blue clay beds, in such a manner as to imply
that the mass had been undermined when the clav
was deposited, unless we suppose, as some have done,
that this chalk is a great detached mass enveloped by

Ch. XIII]

PROTRUDED MASSES OF CHALK.

tertiary strata. For, as one of the " Needles," or in-
sulated rocks of chalk, which stood 120 feet above
high-water mark, at the western extremity of the Isle
of Wight, fell into the sea in 1772 *, so a pinnacle of
chalk may have been precipitated into the tertiary sea,
a t a point where some beds of clay had previously ac-
cumulated. The strata of chalk with flint in the above
diagram appear nearly horizontal ; but they are in fact
highly inclined inwards towards the cliff, and it is quite
evident that the chalk and overlying deposit have both
been subjected to the same movement, and have been
v iolently disturbed.

Since I first published my observations on these
phenomena, I have visited Denmark, and seen similar
appearances, but on a much grander scale, in the cliffs
of the island of Moen. The white chalk with flints,
Which there forms cliffs from 300 to 400 feet high, is
covered with tertiary sand, clay, and loam, exactly re-
sembling in form, colour, and mineralogical character,
the deposit overlying the crag of Norfolk. The chalk
m Moen exhibits curved, vertical, and shifted strata,
Upon the whole more deranged than those of Purbeck
or the Isle of Wight. They have been so fissured and
dislocated, that large masses of overlying clay and sand
have subsided bodily into large chasms, intersecting
the chalk to the depth of several hundred feet. Some
of these intercalations and intermixtures of tertiary
clay and sand with chalk can only be explained by
supposing engulphments of superincumbent matter,
such as are known to have occurred during modern
earthquakes.

I have stated that the Danish tertiary deposit re-

* Dodsley's Annual Register, vol. xv. p. HO,

1 [

ill

!il

I.
1
1 ' 1

I 1

■

•

OLDER PLIOCENE PERIOD.

[Book IV.

sembles that of uncertain age, which rests upon the
crag in Norfolk and Suffolk. The correspondence ex-
tends not merely to the nature of the clay, sand, gravel,
and mud, but to many other peculiarities. Thus in
Denmark, especially in Holstein, as seen in sections on
the banks of the Elbe, we find in some places a total ab-
sence of stratification, while masses in immediate con-
tact are regularly divided into thin layers of sand and
loam extending to the thickness of several hundred feet.
In Denmark also, as in Norfolk, we find here and there
the wreck of many secondary formations included in
the newer deposit, especially chalk, together with
some pebbles of granite, porphyry, and other rocks.
Organic remains are rare in Denmark, except those
derived from older strata, and hence the age of the
formation is on the whole very doubtful ; but it has
been supposed by Dr. Forchhammer and Dr. Beck to
have been in progress throughout more than one ter-
tiary period. Be this as it may, it is ascertained that
one portion of it is extremely modern, and belongs to
the latest part of the Newer Pliocene period, contain-
ing shells identical with those now living in the Ger-
man Ocean. Whether the beds of the Norfolk cliffs
which, together with the chalk, have been so much dis-
turbed, are of equally modern date, or belong rather to
a more remote part of the great Pliocene epoch, is a
point which we cannot yet determine ; and indeed we
cannot hope to solve this problem, until we have com-
pared more attentively the newer tertiary strata of
Denmark, and the south of Sweden, with those of the
eastern coast of England.

CHAPTER XIV.

VOLCANIC ROCKS OF THE OLDER PLIOCENE PERIOD.

gtteous rocks of this period in Italy — Volcanic region of Olot,
1J i Catalonia — Lava currents — Ravines — Ancient alluvium

Jets of air called " Bufadors " (p. 98.)

Age of the Ca-

talonian volcanos uncertain — Earthquake of Olot in 1421
Sardinian volcanos — District of the Eifel and Lower Rhine
Peculiar characteristics of the Eifel volcanos — Lake craters

(p. 102.) Trass — Age of the Eifel volcanic rocks how far

• uncertain (p. 109.) — Brown coal formation.

Italy. — It is part of my proposed plan to consider the
^neous as well as the aqueous formations of each
Period ; but I am far from being able as yet to assign
to each of the numerous groups of volcanic origin scat-
tered over Europe a precise place in the chronological
Se ries. It has been already stated, that the volcanic
r ocks of Tuscany belong, in part at least, to the Older
Miocene period, — those, for example, of Radicofani,
viterbo, and Aquapendente, which have been chiefly
er upted beneath the sea. The same observation
^ould probably hold true in regard to the igneous
r ocks of the Campagna di Roma.

But several other districts, of which the dates are
stl H uncertain, may be mentioned in this chapter as
e ^ n g possibly referable to the period now under con-
sideration. It will at least be useful to explain the
points which require elucidation before the exact age
of the groups about to be described can be accurately
determined.

OLDER PLIOCENE PERIOD.

[Book IV.

I shall first de-

scribe a district of extinct volcanos in the north of
Spain, which is little known, and which I visited in
the summer of 1830.

The whole extent of country occupied by volcanic
products in Catalonia is not more than fifteen geogra-
phical miles from north to south, and about six from
east to west. The vents of eruption range entirely
within a narrow band running north and south ; and
the branches, which are represented as extending

Fig. 131.

Volcanic district of Catalonia.

Pis

/, . cheL

2, Monte

Jxzcouroni

5,0

"| set'. ar

//v

)

//////'AV ////'/////

/// ()///// '/'//y

rid.

"J fo

Vo I

Ch. XIV.]

VOLCANOS OF CATALONIA.

eastward in the map, are formed simply of two lava-

streams

those of Castell Follit and Cellent.

D r. Macl _, p

^° niade known the existence of these volcanos * ;
ncl 5 according to his description, the volcanic region
ended over twen ty square leagues, from Amer to

assanet.

Mas

anet, in the Pyrenees, for traces of a lava-current; and
c an say, with confidence, that the adjoining map gives

c °rrect view of the true area of the volcanic action.

The eruptions

Ve burst entirely through secondary rocks, composed
ln great part of grey and greenish sandstone and con-
glomerate, with some thick beds of nummulitic lime-
stone. The conglomerate contains pebbles of quartz,

ltn estone, and Lydian stone. The limestone i,s not

° n v replete with nummulites, but occasionally in-

clu des oysters, pectens, and other shells. This system

rocks is very extensively spread throughout Cata-

0ril a ; one of its members being a red sandstone, to
^hich the celebrated salt-rock of Cardona is subor-
Um ate. It is conjectured that the whole belongs to

e age of our green-sand and chalk.

■^ear Amer, in the Valley of the Ter, on the south-

rri borders of the region delineated in the map, pri-
ar y rocks are seen consisting of gneiss, mica-schist,
u clay-slate. They run in a line nearly parallel to
e Pyrenees, and throw off the secondary strata from
eir flanks, causing them to dip to the north and
. ort h-west. This dip, which is towards the Pyrenees,

s connected with a distinct axis of elevation, and pre-
s trough the whole area described in the map, the

Maclure, Journ. de Phys., vol. lxvi. p. 219., 1808 5 cited by
aubeny, Description of Volcanos, p. 24.

I 1

fll

•

OLDER PLIOCENE PERIOD.

[Book IV.

face.

inclination of the beds being sometimes at an angle of
between 40 and 50 degrees.

It is evident that the physical geography of the
country has undergone no material change since the
commencement of the era, of the volcanic eruptions,
except such as has resulted from the introduction of
new lulls of scoriae, and currents of lava upon the sur-
**~ If the lavas could be remelted and poured out
again from their respective craters, they would descend
the same valleys in which they are now seen, and re-
occupy the spaces which they at present fill. The only
difference in the external configuration of the fresh
lavas would consist in this, that they would nowhere
be intersected by ravines, or exhibit marks of erosion
by running water.

Volcanic cones and lavas There are about four-
teen distinct cones with craters in this part of Spain,
besides several points whence lavas may have issued ;
all of them arranged along a narrow line running north
and south, as will be seen in the map. The greatest
number of perfect cones are in the immediate neigh-
bourhood of Olot, some of which are represented in
the annexed plate (PL XI.) ; and the level plain on
which that town stands has clearly been produced
by the flowing down of many lava-streams from those
hills into the bottom of a valley, probably once of

considerable depth, like those of the surrounding
country.

In this plate an attempt is made to represent by
colours the different geological formations of which
the country is composed* The blue line of moun-

* This view is taken from a sketch which I made on the spot
in 1830.

c h. XIV.]

VOLCANOS OF CATALONIA.

teins in the distance are the Pyrenees, which are to
the north of the spectator, and consist of primary
a nd ancient secondary rocks. In front of these are
the secondary formations described in this chapter,
coloured grey. Different shades of this colour are
Produced, to express various distances. The flank
°f the hill, in the foreground, called Costa de Pujou,
*s composed partly of secondary rocks, and partly of
v olcanic, the red colour expressing lava and scoriae.

The Fluvia, which flows near the town of Olot, has
cut to the depth of only 40 feet through the lavas of
the plain before mentioned. The bed of the river is
hard basalt ; and at the bridge of Santa Madalena are
seen two distinct lava-currents, one above the other,

separated by a horizontal bed of scoriae eight feet
thick.

In one place, to the south of Olot, the even surface
of the plain is broken by a mound of lava, called the
Bosque de Tosca," the upper part of which is scori-
aceous, and covered with enormous heaps of fragments
of basalt more or less porous. Between the numerous
hummocks thus formed are deep cavities, having the
v appearance of small craters. The whole precisely re-
sembles some of the modern currents of Etna, or that
of Come, near Clermont ; the last of which, like the
•Bosque de Tosca, supports only a scanty vegetation.

Most of the Catalonian volcanos are as entire as
those in the neighbourhood of Naples, or on the flanks
of Etna. One of these, figured in the plate, called
Montsacopa, is of a very regular form, and has a cir-
cular depression or crater at the summit. It is chiefly
toade up of red scoriae, undistinguishable from that of
the minor cones of Etna. The neighbouring hills of
Olivet and Garrinada, also figured in the plate, are of

< r

OLDER PLIOCENE PERIOD,

[Book IV.

similar composition and shape. The largest crater of
the whole district occurs farther to the east of Olot,

Marga

It is 455 feet deep

and about a mile in circumference. Like Astroni,
near Naples, it is richly covered with wood, wherein
game of various kinds abounds.

Although the volcanos of Catalonia have broken out
through sandstone, shale, and limestone, as have those
of the Eifel, in Germany, to be described in the sequel,
there is a remarkable difference in the nature of the
ejections composing the cones in these two regions.
In the Eifel, the quantity of pieces of sandstone and
shale thrown out from the vents is often so immense
as far to exceed in volume the scoriae, pumice, and
lava ; but I sought in vain in the cones near Olot for
a single fragment of any extraneous rock ; and Don
Francisco Bolos, an eminent botanist of Olot, informs
me that he has never been able to detect any. Vol-
canic sand and ashes are not confined to the cones,
but have been sometimes scattered by the wind over
the country, and drifted into narrow valleys, as is seen
between Olot and Cellent, where the annexed section
is exposed. The light cindery volcanic matter rests
in thin regular layers, just as it alighted on the slope
formed by the solid conglomerate. No flood could

a. Secondary conglo-

merate.

6. Thin seams of vol-
canic sand and scoria?.

have passed through the valley since the scoria fell, or
these would have been for the most part removed.
The currents of lava in Catalonia, like those of

Ch - XIV.] RAVINES IN LAVA EXCAVATED BY RIVERS. 95

uvergne, the Vivarais, Iceland, and all mountainous

countries, are of considerable depth in narrow defiles,

JJt spread out into comparatively thin sheets in places

ere the valleys widen. If a river has flowed on

e arly level ground, as in the great plain near Olot,

e w ater has only excavated a channel of slight depth;

u where the declivity is great, the stream has cut

th Ge ^ section > som etimes by penetrating directly

f ° u gh the central part of a lava-current, but more

gently by passing between the lava and the se-

° ndar y rock which bounds the valley. Thus, in the

Cot npanying section, at the bridge of Cellent, six

1 es east of Olot, we see th e lava on one side of the

Q Section above the bridge of Cellent.

6 * ^ c °riaceous lava.

c ' ^ ch istose basalt.

' Colu mnar basalt.

d. Scoriae, vegetable soil, and alluvium.

e. Nummulitic limestone.

/. Micaceous grey sandstone.

stream ; while the inclined stratified rocks con-

of v^ t * le c ^ anne ^ anc * opposite bank. The upper part
j. e lava at that place, as is usual in the currents of
c a anc * Vesuvius, is scoriaceous ; farther down it be-
St'll eS P orous > and assumes a spheroidal structure;
t , ° Wer lt divides in horizontal plates, each about
inches in thickness, and is more compact. Lastly,

■ in

OLDER PLIOCENE PERIOD.

[Book IV'

at the bottom is a mass of prismatic basalt about five
feet thick. The vertical columns often rest immediately
on the subjacent secondary rocks ; but there is some-
times an intervention of such sand and scoria? as cover
the country during volcanic eruptions, and which when
unprotected, as here, by superincumbent lava, is
washed away from the surface of the land. Some-
times, the bed d contains a few pebbles and angular
fragments of rock; in other places fine earth, which
may have constituted an ancient vegetable soil.

In several localities, beds of sand and ashes are in-
terposed between the lava and subjacent stratified
rock, as may be seen if we follow the course of the
lava-current which descends from Las Planas towards
Amer, and stops two miles short of that town. The
river there has often cut through the lava, and through
eighteen feet of underlying limestone. Occasionally
an alluvium, several feet thick, is interspersed between
the igneous and marine formation; and it is interesting
to remark that in this, as in other beds of pebbles
occupying a similar position, there are no rounded
fragments of lava ; whereas in the most modern gravel-
beds of rivers of this country, volcanic pebbles are
abundant.

The deepest excavation made by a river through
lava, which I observed in this part of Spain, is that
seen in the bottom of a valley near San Feliu de Pal-
lets, opposite the Castell de Stolles. The lava there
has filled up the bottom of a valley, and a narro*
ravine has been cut through it to the depth of one
hundred feet. In the lower part the lava has »
columnar structure. A great number of ages were
probably required for the erosion of so deep a ravine ;
but we have no reason to infer that this current is of

Ill

** XIV.] RAVINES IN LAVA EXCAVATED BY RIVERS. 97

higher antiquity than those of the plain near Olot.

A he fall of the ground, and consequent velocity of the

stream, being in this case greater, a more considerable

y olume of rock may have been removed in the same
time.

* shall describe one more section to elucidate the
Phenomena of this district. A lava-stream, flowing

r om a ridge of hills on the east of Olot, descends a
considerable slope, until it reaches the valley of the
river Fluvia. Here, for the first time, it comes in
c °ntact with running water, which has removed a
Portion, and laid open its internal structure in a pre-
Cl pice about 130 feet in height, at the edge of which
stands the town of Castell Follit.
% the junction of the rivers Fluvia and Teronel

ne mass of lava has been cut away on two sides ; and

Probabl

(Fig. 134.)

y never so high as the cliff a, as it may have
instituted the lower part of the sloping side of the
0ri ginal current.

From an examination of the vertical cliffs, it appears
hat the upper part of the lava on which the town is
Uu t is scoriaceous, passing downwards into a sphe-
ral basalt; some of the huge spheroids being no
ess than six feet in diameter. Below this is a more
Coi »pact basalt with crystals of olivine. There are in
about four distinct ranges of prismatic basalt, separ-
ated by thinner beds not columnar, and some of which
re schistose. The whole mass rests on alluvium, ten
or twelve feet in thickness, composed of pebbles of
• Iftl estone and quartz, but without any intermixture of
goeous rocks ; in which circumstance alone it appears

to diff.

er from the modern gravel of the Fluvia

V OL.iv.

. *

,,.^-

^^^^

OLDER PLIOCENE PERIOD.

[Book IV.

Fig. 134

Section at Castell Follit.

A. Church and town of Castell Follit, overlooking precipices of

basalt.

B. Small island, on each side of which branches of the river

Teronel flow to meet the Fluvia.

c. Precipice of basaltic lava, chiefly columnar, about 1 30 feet in

height.

d. Ancient alluvium underlying the lava-current.

e. Inclined strata of secondary sandstone.

Bvfadors. — The volcanic rocks near Olot have often
a cavernous structure, like some of the lavas of E tna
and in many parts of the hill of Batet, in the environs
of the town, the sound returned by the earth, when
struck, is like that of an archway. At the base of the
same hill are the mouths of several subterranean
caverns, about twelve in number, which are called in
the country " bufadors," from which a current of cold
air issues during summer, but which in winter is said
to be scarcely perceptible. I visited one of these
bufadors in the beginning of August, 1830, when the
heat of the season was unusually intense, and found a
cold wind blowing from it ; which may easily be ex-

.- "

*■
*

Ch. XIV.]

AGE OF CATALONIAN VOLCANOS.

plained ; f or as the external air, when rarefied by heat,
ascends, the pressure of the colder and heavier air of
the caverns in the interior of the mountain causes it
to rush out to supply its place.

It now

on y remains to offer some remarks on the probable
a £ e of these Spanish volcanos. Attempts have been
m ade to prove, that in this country, as well as in Au-
Ver gne and the Eifel, the earliest inhabitants were eye-
witnesses to the volcanic action. In the year 1421, it
ls said, when Olot was destroyed by an earthquake,
au eruption broke out near Amer, and consumed the

own. The researches of Don Francisco Bolos have,
think, shown, in the most satisfactory manner, that

her e is no good historical foundation for the latter

P ar t of this story ; and any geologist who has visited

^er must be convinced that there never was any

Option on that spot. It is true that, in the year above

Mentioned, the whole of Olot, with the exception of a

^gle house, was cast down by an earthquake ; one
those shocks which, at distant intervals during the

; st fi y e centuries, have shaken the Pyrenees, and par-

^ularly the country between Perpignan and Olot,
er e the movements, at the period alluded to, were
m °st violent.

°°*ne houses are said to have sunk into the earth ;

t h tllis account has been corroborated by the fact

a t, within the memory of persons now living, the

r ied arches of a Benedictine monastery were found

j ^e depth of six feet beneath the surface ; and still

er > some houses were dug out in the street called

gua. D on Bolos informed me, that he was present

a the latter excavation was made, and when the

°f a buried house was found nearly entire ; the

f 2

100

OLDER PLIOCENE PERIOD.

[Book IV

interior of the building being in a great part empty, so
that is was necessary to fill it up with earth and
stones, in order to form a sure foundation for the new
edifice.

The annihilation of the ancient Olot may, perhaps,
be ascribed, not to the extraordinary violence of the
movement on that spot, but to the cavernous nature of
the subjacent rocks ; for Catalonia is beyond the line
of those European earthquakes which have, within the
period of history, destroyed towns throughout exten-
sive areas.

As we have no historical records, then, to guide us
in regard to the extinct volcanos, we must appeal to
geological monuments. I have little doubt that some
fossil land-shells, and bones of quadrupeds, will here-
after reward the industry of collectors. If such re-
mains are found imbedded in volcanic ejections, the
period of the eruptions may be inferred ; but at pre-
sent we have no evidence beyond that afforded by
superposition, in regard to which the annexed diagram
will present to the reader, in a synoptical form, the
results obtained from numerous sections.

Fig. 135.

Superposition of rocks in the volcanic district of Catalonia.

Sandstone and nummulitic limestone.

b. Older alluvium without volcanic pebbles.

Cones of scorias and lava.

d. Newer alluvium

The more modern alluvium, d 9 is partial, and has
been formed by the action of rivers and floods upon the

Ch. XIV.]

VOLCANOS OF THE EIFEL.

101

lava; whereas the older gravel, b, was strewed over
the country before the volcanic eruptions. In neither
have any organic remains been discovered ; so that we
can merely affirm, as yet, that the volcanos broke out
after the elevation of some of the newest rocks of the
secondary series, and before the formation of an allu-
v ^m, d, of unknown date- The integrity of the cones

Merely shows that the country has not been agitated

ky violent earthquakes, or subjected to the action of
any great transient flood since their origin.

East of Olot, on the Catalonian coast, marine tertiary
st ^ata occur, which, near Barcelona, attain the height
°f about five hundred feet. It appears probable, from
a small number of shells which I collected, tbat these
strata may correspond with the Subapennine beds;
s ° that if the volcanic district had extended thus far,
^e might be able to determine the age of the igneous
products, by observing their relation to these Older

■Pliocene formations. *

Sardinian volcanos. — The line of extinct volcanos
*** Sardinia, described by Captain Smyth f, is also of
Ul *certain date, as, notwithstanding the freshness of
s ome of the cones and lavas, they may be of high an-
Equity. They rest, however, on a tertiary formation,
supposed by some to correspond to the Subapennine
str ata, but of which the fossil remains have not been
fully described.

Volcanic rocks of the Eifel. — The volcanos of the
Lower Rhine and the Eifel are, for the most part, of no

■

For some account of the Olot volcanos, see " Noticia de los
Estinguidos Volcanes de la Villa de Olot," by Francisco Bolos.
Barcelona. No date ; but the observations, I am told, preceded
those of Dr. Maclure.

t Present State of Sardinia, &c. pp. 69, 70.

F 3

102

OLDER PLIOCENE PERIOD.

[Book IV,

less uncertain date than those of Catalonia ; but I am
desirous of pointing out some of their peculiar charac-
ters, and shall, therefore, treat of them in this chapter,
trusting that future investigations will determine their
chronological relations more accurately.

For the geographical details of this volcanic region
the reader is referred to thea nnexed map (Fig. 1 36.),
for which I am indebted to Mr. Horner, whose resi-
dence in the country has enabled him to verify the
maps of MM. Noeggerath and Von Oeynhausen, from
which that now given has been principally compiled.

There has been a long succession of eruptions in
this country, and some of them must have occurred
when its physical geography was in a very different
state, while others have happened when the whole dis-
trict had nearly assumed its present configuration.

The fundamental rock of the Eifel is an ancient
secondary sandstone and shale, to which the obscure
and vague appellation of « grey wacke" " has been given.
The formation has precisely the characters of a great
part of those gray and red sandstones and shales,
which are called " old red sandstone " in England and
Scotland, where they constitute the inferior member
of the carboniferous series. In the Eifel they occupy
the same geological position, and in some parts alter-
nate with a limestone, containing trilobites and other
fossils of our "mountain" and « transition" limestones.
The strata are inclined at all angles, from the hori-
zontal to the vertical, and must have undergone re-
iterated convulsions before the country was moulded
into its present form.

Lake-craters. — The volcanos have broken out some-
times at the bottom of deep valleys, sometimes on
the summit of hills, and frequently on intervening

Ch. XIV.]

VOLCANIC DISTRICT OF THE EIFEL.

103

*>.

^«-

« CO —

-a

■5 H -3 & ^

o o o o Sd

.gtS

o3 '£

•

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• rH

82
o

c/i

*-<

• 1H

03
O

c
o

8 S

PPM

O 03
CO

PQ <*-« *

03
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x g. 1 36.

104

OLDER PLIOCENE PERIOD.

[Book IV.

platforms. The traveller often falls upon them unex-
pectedly in a district otherwise extremely barren of

geological interest.

us, for example, he might

arrive at the village of Gemund, immediately south of
Daun, without suspecting that he was in the imme-
diate vicinity of some of the most remarkable vents of
eruption. Leaving a stream, which flows at the bottom
of a deep valley in a sandstone country, he climbs the
steep acclivity of a hill, where he observes the edges
of strata of sandstone and shale dipping inwards to-

^ q

0»

«J

o ^

a) q

Q o

;

Ch. XIV.]

LAKE-CRATERS OF THE EIFEL.

105

^ards the mountain. When he has ascended to a con-
siderable height, he sees fragments of scoriae sparingly
scattered over the surface ; till, at length, on reaching
the summit, he finds himself suddenly on the edge of
a torn, or deep circular lake-basin.

Tn . _ _ _

Maar

™*t of three lakes which are in immediate contact,
e same ridge forming the barrier of two neighbouring
cavities (see Fig. 137.)- On viewing the first of these
w e recognize the ordinary form of a crater, for which
^ e have been prepared by the occurrence of scoriae
scattered over the surface of the soil. But on examin-
ln g the walls of the crater, we find precipices of
sandstone and shale which exhibit no signs of the
ac tion of heat ; and we look in vain for those beds of
lav a and scoriae, dipping in opposite directions on every
side, which we have been accustomed to consider as
characteristic of volcanic craters. As we proceed,
however, to the opposite side of the lake, and after-
wards visit the craters c and d (Fig. 138.), we find a
c °nsiderable quantity of scoriae and some lava, and
Se e the whole surface of the soil sparkling with vol-
c anic sand, and strewed with ejected fragments of
nalf-f usec j s hale, which preserves its laminated texture

lXi the interior, while it has a vitrified or scoriform
ating.

^ A few miles to the south of the lakes above men-
tioned occurs the Pulvermaar of Gillenfeld, an oval
a ke of very regular form, and surrounded by an un-
r oken ridge of fragmentary materials, consisting of
Jected shale and sandstone, and preserving a uniform
hei ght of about 150 feet above the water. The side
^ ,0 Pe in the interior is at an angle of about forty-five
de grees ; on the exterior, of thirty-five degrees. Vol-

f 5

tot

106

OLDER PLIOCENE PERIOD.

[Book IV.

canic substances are intermixed very sparingly with
the ejections, which in this place entirely conceal from
view the stratified rocks of the country.*

The Meerfelder Maar is a cavity of far greater size
and depth, hollowed out of similar strata ; the sides
presenting some abrupt sections of inclined secondary
rocks, which in other places are buried under vast
heaps of pulverized shale. I could discover no scoriae
amongst the ejected materials, but balls of olivine
and other volcanic substances are mentioned as having
been found.f This cavity, which we must suppose to
have discharged an immense volume of gas, is nearly
a mile in diameter, and is said to be more than one
hundred fathoms deep. In the neighbourhood is a
mountain called the Mosenberg, which consists of red
sandstone and shale in its lower parts, but supports
on its summit a triple volcanic cone, while a distinct
current of lava is seen descending the flanks of the
mountain. The edge of the crater of the largest cone
reminded me much of the form and characters of that
of Vesuvius.

If we pass from the Upper to the Lower Eifel, we
find the celebrated lake-crater of Laach, which has a
greater resemblance than any of those before men-
tioned to the Lago di Bolsena, and others in Italy
being surrounded by a ridge of gently sloping hills,
composed of loose tuffs, scoriae, and blocks of a variety
of lavas.

■

One of the most interesting volcanos on the left
bank of the Rhine is called the Roderberg. It forms
a circular crater nearly a quarter of a mile in diameter,
and one hundred feet deep, now covered with fields of

* Scrope, Edin. Journ. of Sci., June, 1826, p. 145.
f Hibbert, Extinct Volcanos of the Rhine, p. 24.

Ch. XIV,]

LAKE-CRATERS OF THE EIFEL.

107

corn. The highly inclined greywack£ strata rise even
to the rim of one side of the crater ; but they are over-
spread by quartzose gravel, and this again is covered
by volcanic scoriae and tufaceous sand. The opposite
wall of the crater is composed of cinders and scorified
r ock, like that at the summit of Vesuvius. It is quite
evident that the eruption in this case burst through
the greywacke and alluvium which immediately over-
lies it; and I observed some of the quartz pebbles
*nixed with scoriae on the flanks of the mountain, as if
they had been cast up into the air, and had fallen again

with the volcanic ashes.

I have already observed, that a large part of this
crater has been filled up with loess, and I have pointed
out how far we may thus obtain a relative date for the

period of its eruption.*

The most striking peculiarity of a great many of the
craters above described, is the absence of any signs of
alteration or torrefaction in their walls, when these are
composed of regular strata of greywacke-sandstone and
>. It is evident that the summits of hills formed

shale.

of the above-mentioned stratified rocks have, in some

cases, been carried away by gaseous explosions, while
at the same time no lava, and often a very small quan-
tity only of scoriae, has escaped from the newly formed
cavity. There is, indeed, no feature in the Eifel vol-
canos more worthy of note, than the proofs they afford
of very copious aeriform discharges, unaccompanied
by the pouring out of melted matter, except, here and
there, in very insignificant volume. I have seen no
assemblage of extinct volcanos in France, Italy, or
Spain, where gaseous explosions of such magnitude

* See p. 34.

F 6

'•

•

108

OLDER PLIOCENE PERIOD.

[Book IV.

Maar

have been attended by the emission of so small a
quantity of lava. Yet I looked in vain in the Eifel for
any appearances which could lend support to the hy-
pothesis, that the sudden rushing out of such enormous
volumes of gas had ever lifted up the stratified rocks
immediately around the vent, so as to form conical
masses, having their strata dipping outwards on all
sides from a central axis. In the Gemunder
the beds, as before stated, have an inward dip on one
side of the hill ; and in the walls of this and other cra-
ters, there are strata which are inclined at all angles,
just as may be observed in the greywacke, far from the
points of eruption. Those who favour the theory of
the elevation crater might naturally expect, that in a
district where so many tremendous explosions have
occurred, they would find masses of greywacke" tower-
ing several thousand feet above the surrounding plat-
form, whereas the height of these ancient rocks has
not been visibly affected by the sites of the extinct
volcanos.*

Trass and its origin — It appears that in the Lower
Eifel eruptions of trachytic lava preceded the emission
of currents of basalt, and that immense quantities of
pumice were thrown out wherever trachyte issued.
In this district, also, we find the tufaceous alluvium of
the Rhine volcanos called trass, which has covered
large areas, and choked up some valleys now partially
re-excavated. This trass is unstratified ; and its base
consists almost entirely of pumice, in which are in-
cluded fragments of basalt and other lavas, pieces of
burnt shale, slate, and sandstone, and numerous trunks
and branches of trees.

* See Vol. II. p. 152

AGE OF THE EIFEL VOLCANOS.

109

Ch. XIV.]

We may easily conceive the manner of its origin, if
we reflect on what would happen if an eruption, at-
tended by a copious evolution of gases, should now
occur in one of the lake basins. The water might re-
main for weeks in a state of violent ebullition, until it
hecame of the consistency of mud, just as the sea con-
tinued to be charged with red mud round Graham's

Island, in

a breach should then be made in the side of the cone,
the flood would sweep away great heaps of ejected
fragments of shale and sandstone, which would be
borne down into the adjoining valleys. Forests might
be torn up by such a flood ; and thus the occurrence
of the numerous trunks of trees dispersed irregularly
through the trass, can be explained.

Mediterranean

(Fig. 136.)

It will be seen by the

the opposite or right bank of the Rhine, where they

Wes

great mass of the mountains called the Siebengebirge.
They consist partly of basaltic and partly of trachytic
lavas, the latter description being, in general, the more
ancient of the two. There are many varieties of tra-
chyte, some of which are highly crystalline, resem-

blin

g a

_ coarse-grained granite, with large separate
crystals of felspar. Trachytic tuff is also very abund-
ant. It is a difficult task to determine the age of all
these igneous rocks, although their position, relatively
to the stratified formations with which they are asso-
ciated, has been clearly made out. The accompanying
table presents in a synoptical view the series of r

ocks

(Fig. 136.)

* See Vol. II. p. 147

OLDER PLIOCENE PERIOD.

[Book IV.

a. Volcanic.

b. Loess#

c. Gravel.
b. L<oess.
a. Volcanic.

d. Volcanic.

e. Gravel,

/ Brown coal.
g. Volcanic.
f. Brown coal.

Greywacke'. C.

A. Newer Pliocen

B ' T thlnAr ° f UnCertain P*** but °u<*

to 111^ *-V h ? the PeyncU C ' befOTe ^'""ed

(P- 102.), ,s the lowest rock of the series, which is

usually m higMy inclined strata • <* »

loose sand and ^t^^TSr^

ironstone and siliceous conglomerate. Bed s of Sg

brown and sometimes black Ii g „i, e , rf various t ,S
ness, are lnterstratified with the clav<, »n,i V
often irregular,, di ffuS ed fl^?^ ^ £

^ , y cont ^m numerous im-

pressions of leaves and stems of trees . Jn "al

places layers of trachytic tuff a « • . . .„ several

in these tuffs are leaves of *£j??TF t " d

found in the brown coal, hTw n f tC 7 T

period of the accumulation of thTfaL f ^

products fr) were ejected. ^ S ° me Volcanic

A vast deposit of gravel e nW a

pebb.e, of white ouarl *?£&?£?£

fragments of other rocks, lies over the brown cod
formation, forming sometimes only a thin covering at

others attaining a thickness of more than loo feet.

f^^

Ch -XlV.] . AGE OF EIFEL" VOLCANOS. HI

■

A nis gravel is very distinct in character from that now
Arming the bed of the Rhine. It is called « Kiesel
Scrolle" by the Germans, often reaches great eleva-
lon s, and is covered in several places with volcanic
J e ctions. It is evident that the country has under-
gone great changes in its physical geography since
ftls gravel was formed, whereas no inconsiderable
Proportion of the volcanic rocks, d, were produced

te r the country had nearly attained its present con-
figuration.

-I he aqueous and igneous formations above enume-

a * e d, constituting the group B, may be, declared to be
te rtiary, from the character of the organic remains of

*/.

^ have been shown to be so intimately connected with
^ e loess *, that we may, without hesitation, declare

e *n to belong to the Newer Pliocene period. It

sh °uld be recollected, however, that the whole series

"^ only forms, in the aggregate, a very insignificant

e ature in the district, and the great mass of the vol-

^ a nic products, d, may, possibly, belong to the Older

hocene, or some still more remote era.
The varieties of wood found in the brown coal strata
are said to belong entirely to dicotyledonous trees;

ut among the impressions of leaves, collected by
1 * r * Horner, some were referred by Mr. Lindley to a
P^tti, perhaps of the genus Chamserops, and others re-
Se *nbled the Cinnamomum dulce, and Podocarpus ma-

Cr °phylla, which would also indicate a warm climate, f
The other organic remains of the brown coal are

* See pp. 32. 34.

f Trans, of Geol. Soc, 2d ser. vol. v

\ .

112

OLDER PLIOCENE PERIOD.

[Book IV.

principally fishes; they are found in a bituminous
shale, called paper-coal, from being divisible into ex-
tremely thin leaves. The individuals are extremely
numerous; but they appear to belong to about five
species, which M. Agassiz informs me are all extinct,
and hitherto peculiar to this brown coal. They belong
to the freshwater genera Leuciscus, Aspius, and Perca-
The remains of frogs also, of an extinct species, have
been discovered in the paper-coal; and a complete
series may be seen in the museum at Bonn, from the
most imperfect state of the tadpole to that of the full

grown animal. With

salamander, scarcely

• — it

distinguishable from the recent species, has been found,
and several remains of insects.

The brown coal was evidently a freshwater form-
ation ; but the extreme rarity of shells renders it diffi-
cult to form any conjecture as to the subdivision of
the tertiary period to which it may belong. Near
Marienforst, in the vicinity of Bonn, large blocks are
found of a white opaque chert, containing numerous
casts of freshwater shells, which appear to belono- to
Planorbis rotundatus and Limnea longiscata, two spe-
cies common both to the Eocene and Miocene periods,
but which have not been found in any newer deposits.

to whom I showed the specimens, said
he felt as confident of the above identifications as mere
casts would warrant. These blocks of chert are not
in situ, but they probably belong to the brown coal
formation, of which the hills at Marienforst consist.
The brown coal is well known to contain, at other
places, subordinate beds of silex. It is to be hoped,
that a comparison of the organic remains of the brown

of Miocene

Mayen

Ch. XIV.]

AGE OF EIFEL VOLCANOS.

113

ugh t on the chronological relations of the igneous and
freshwater formations above considered.*

For fuller details consult Noeggerath's Rheinland West-
Pnalen, Memoirs of Von Dechen, Oeynhausen, and Von Buch,
Steininger (erloschenen Vulkane in der Eifel, &c., Mainz, 1820),
Va n der Wyck (Uebersicht der Rheinischen und Eifeler
erl osch, Vulkane, Bonn. 1826), Scrope (Edin. Journ. of Sci.
26 3 p. 145.), Daubeny (Volcanos, p. 45.)? Leonhard (Ueber
Basalt- Gebilde), Hibbert (Extinct. Voles, of Rhine), and the
Memoir above cited by Mr. Horner, in the Trans, of Geol. Soc.
Vo1 - v. 2d ser.

114

CHAPTER XV.

MIOCENE FORMATIONS — MARINE

Miocene period — Marine formations — Faluns of Touraine
compared to the English crag — Basin of the Gironde and
Landes — Freshwater limestone of Saucats (p. 121.) — Eocene
strata in the Bordeaux basin. — Position of the limestone of
Blaye — Inland cliff near Dax — Montpellier — Strata of
Piedmont — Superga — Valley of the Bormida — Molasse of
Switzerland (p. 128.) — Basin of Vienna — Styria^ — Hun*
gary — Volhynia and Podolia — Mayence.

Having treated in the preceding chapters of the Older
and Newer Pliocene formations, I shall next consider
those members of the tertiary series for which I have
proposed the name of Miocene. The distinguishing
characters of this group, as derived from its imbedded
fossil testacea, have been explained in the fifth chap-
ter.* In regard to the relative position of the strata,
they underlie the Older Pliocene, and overlie the
Eocene, formations, when any of these happen to be
present.

The area covered by the marine, freshwater, and
volcanic rocks of the Miocene period, in different parts
of Europe, can already be proved to be very consider-
able ; for they occur in Touraine, in the basin of the
Loire, and still more extensively in the South of

* Vol. III. p. 370.

■ -

fel

F=3

Crs

rC-

^ ~

er>

^n)

1
I

1 >~:

2 I

k ^

rs3

r-v

> 1

■

^^-

c h. XV.]

FALUNS OF TOURAINE.

115

ra nce, between the Pyrenees and the Gironde. They

( av e also been observed in Piedmont, near Turin, and

" e neighbouring valley of the Bormida, where the

pennines branch off from the Alps. They are largely

veloped in the neighbourhood of Vienna and in

y ri a; they abound in parts of Hungary; and they

ers pread extensive tracts in Volhynia and Podolia.

, °nells characteristic of the Miocene strata are found

all these countries, figures of some of which are

? er * in Plate XII., the species here selected abounding

. a '^ost all the deposits of this era, and not occurring

any Eocene or Pliocene formations. Cardita Ajar,

°^ever, is also a recent species, but has been admitted

, n a ccount of its abundance in Miocene strata, and

Ca use it has never yet been observed in any Pliocene

P° s it, and is confined in a living state to tropical

°^tri es> as Senegal.

c «unt

s hall now proceed to notice briefly some of the

°fth

ri es before enumerated as containing monuments

e era under consideration.

°urctine. — I have already alluded to the proofs

s uperp os ition adduced by M. Desnoyers, to show

at the shelly strata provincially called " the Faluns

he Loire," were posterior to the most recent fresh-

er formation of the basin of the Seine. Their

, ltlor *> therefore, shows that they are of newer

§ l fl than the Eocene strata, — more recent, at least,

the uppermost beds of the Paris basin. But an

r *unation of their fossil contents proves also that

tVi are re f era ble to that type which distinguishes

e Miocene period. When 300 of the Touraine

. s collected by M. Desnoyers were compared by

s ' P es hayes with more than 1100 of the Parisian

peci es, there were scarcely more than 20 which could

116

MIOCENE PERIOD.

[Book

IV-

be identified; and on the other hand, the fossil shell 3
of the Touraine beds agree far less with the testace*
now inhabiting our seas than do the shells of the 0\& eX
Pliocene strata of Northern Italy.

It is not merely in the basin of the Loire that the

Mioce

)

(see Map

Miocene

to repose on a great variety of older rocks between
Sologne and the sea, in which line they are seen to rest
successively upon gneiss, clay-slate, coal-measured
Jura limestone, greenstone, chalk, and lastly upon the
upper freshwater deposits of the basin of the Sein^
They consist principally of quartzose gravel, sand, and
broken shells. The components are generally inco-
herent, but sometimes agglutinated together by a cal-
careous or earthy cement, so as to serve as a building
stone. Like the shelly portion of the crag of Norfc^
and Suffolk, the faluns and associated strata are o(
slight thickness, not exceeding seventy feet. They
often bear a close resemblance to the crag in appear*
ance, the shells being stained of the same ferruginous
colour, and being in the same state of decay ; serving
in Touraine, just as in Norfolk and Suffolk, to fertile
the arable land. Like the crag, also, they contain mam'
miferous remains, which are not only intermixed wit* 1
marine shells, but sometimes incrusted with serpul^
flustra, and balani. These terrestrial quadrupeds
belong to the genera Mastodon, Rhinoceros, Hippo-
potamus, &c, the assemblage, considered as a whole
being very distinct from those of the Paris gypsum.

* Desnoyers, Bull, de la Soc. Geol. de France, tome ii. p. 445«

c h. XV.]

CRAG AND FALUNS COMPARED.

117

The faluns and contemporary strata of the basin of
the Loire may be considered generally as having been
f °rmed in a shallow sea, into which a river, flowing
Perhaps from some of the lands now drained by the
^°ire, introduced from time to time fluviatile shells,
*°°d> and the bones of quadrupeds, which may have
beer * washed down during floods. Some of these
"°&es have precisely the same black colour as those
f °und i n t he peaty shell-marl of Scotland ; and we
^ght imagine them to have been dyed black in Mio-
Cene peat, which was swept down into the sea during
tfte waste of cliffs, did we not find the remains of
Cet acea in the same strata— bones, for example, of
the lamantine, morse, sea-calf, and dolphin, having
Precisely the same colour.

The resemblance which M. Desnoyers has pointed
0ut as existing between the English crag and the

Clrc utnstances at the respective periods when each
Was deposited. In every age, where there is land and
Sea > there must be shores, shallow estuaries, and rivers ;
and near the sea-coasts banks of marine shells and
Cora ls may accumulate. It must also be expected

that

rivers will drift in freshwater shells, together

Wlttl sand and pebbles, and occasionally, perhaps,
s ^eep a own the carcasses of land quadrupeds into the
Sea - If the sand and shells, both of the " crag" and

"fal

u ns," have each acquired the same ferruginous
c °Wr, such a coincidence would merely lead us to
lnf er that, at each period, there happened to be springs
ch arged with iron, which flowed into some part of the

drench faluns is one which ought by no means ro m-
duc e us to ascribe a contemporaneous origin to these
l *° groups, but merely a similarity of geographical

■

118

MIOCENE PERIOD.

[Book

* M

sea or basin of the river, by which the sediment was
carried down into the sea.

Even had the French and English strata which we
are comparing shared a greater number of mineral
characters in common, that identity could not have
justified us in inferring the synchronous date of the
two groups, where the discordance of fossil remains
is so marked. The argument which infers a content
poraneous origin from correspondence of mineral con-
tents, proceeds on the supposition that the materials
were either washed down from a common source, oh
being derived from different sources, were mingled
together in a common receptacle. If, according to
the latter hypothesis, the crag and the faluns were
thrown down in one continuous sea, the testacefl
could not have been so distinct in two regions no*
more distant from each other than Essex and the
mouth of the Loire, unless we assume that the laW
which regulated the geographical distribution of spe-
cies were then very different from those now prevail-
ing. But if it be said that the two basins may have
been separated from each other, as are those of the
Mediterranean and Red Sea, by an isthmus, and that
distinct assemblages of species may have flourished
in each, as is now actually the case in those two
seas * I may reply, that such narrow lines of demarc-
ation are extremely rare now, and must have been
infinitely more so in remoter tertiary epochs ; because
there can be no doubt that the proportion of land to
sea has been greatly on the increase in European lati-
tudes during the more modern geological eras.

faluns

•)

See above, chap. x.

BASIN OF THE GIRONDE.

119

Ch. XV.]

^hich occur

°yers has discovered the following mammiferous
Quadrupeds :

dustiden

Hippopoti

m magnum, Mastodon an-
major and H. minutus,

•inoceros leptorhinus and R. minutus, Tapir gigas 9

species)
Rodent

(small species), Sus, Equus (small

la.

-the first species on this list is common to the Paris

§ypsum, and is therefore an example of a land qua-
ru ped common to the Miocene and Eocene formations,

an exception perfectly in harmony with the results

Stained from the study of fossil shells.*
Basin of the Gironde and district of the Landes.-f

^ great extent of country between the Pyrenees and
he Gironde is overspread by tertiary deposits, which
av e been more particularly studied in the environs
1 Bordeaux and Dax, from whence about six hundred
Pecies of shells have been obtained. These shells be-
n g to the same zoological type as those of Touraine/j:
■Most of the beds near Dax, whence these shells
re procured, consist of incoherent quartzose sand,

*** l xed for the most part with calcareous matter, which
as often bound together the sand into concretionary

-For further details respecting the basin of the Loire, see

' ^esnoyers, Ann. des Sci. Nat., tome xvi. pp. 171. 402.,

ere full references to other authors are given.

t Since this account was first written in 1832, M. Dufrenoy's

cie on the tertiary strata of the south of France, has been pub-

lshe d with lists of shells by M. C. Desmoulins. See Memoires

r servir a, une Descrip. Geol. de la France, torn. iii. p. 1.
-^ris* 1836.

+ *&• de Basterot has given descriptions of more than three
Un dred shells of Bordeaux and Dax, and figures of the greater
nUmber of them. M£m. de la Soc. d'Hist. Nat. de Paris, tome ii.

I) J

120

MIOCENE PERIOD.

[Book IV.

nodules. A great abundance of fluviatile shells occurs
in many places intermixed with the marine ; and in
some localities microscopic shells of the order fora-
minifera are in great profusion.

The tertiary deposits in this part of France vary
much in their mineralogical character, yet admit ge-
nerally of being arranged in four groups. See diagram.

Fig. 139.

A dour R.

Luy R. Puy Arzet.

Tertiary strata overlying chalk in the environs of Dax.

a. Siliceous sand without shells.

b. Gravel.

c. Sand and marl with shells.

d. Blue marl with shells.

E. Chalk and volcanic tuff.

In some places the united thickness of these groups
is considerable ; but in the country between the Py-
renees and the valley of the Adour, around Dax, the
disturbed secondary rocks are often covered by a 'thin
pellicle only of tertiary strata, which rests horizontally
on the chalk, and does not always conceal it.

In the valleys of the Adour and Luy, sections of all
the members of this tertiary formation are laid open ;
but the lowest blue marl, which is sometimes two
hundred feet thick, is not often penetrated. On the
banks of the Luy, however, to the south of Dax, the
subjacent white chalk is exposed in inclined and ver-
tical strata. In the hill called Puy Arzet the chalk,
characterized by its peculiar fossils, is accompanied by
beds of volcanic tuff, which are conformable to it, and
which may be considered as the product of submarine
eruptions which took place in the sea wherein the chalk
was formed. These tuffs must once have been nearly

STRATA NEAR DAX.

121

c h. XV.]
h

horizontal, but, like the chalky strata, have been sub-
jected to great subsequent derangement,

-About a mile west of Orthes, in the Bas Pyrenees,

the bl

ue marl is seen to extend to the borders of the

? rtlar y formation, and rises to the height probably of
Slx or seven hundred feet. In that locality many of

th
col

their original

ginous gravel, which seems to in-

e marine Miocene shells preserve
ours. This marl is covered by a considerable
Sickness of ferru
ea se in volume near the borders of the tertiary basin
n the side of the Pyrenees.
■* n an opposite direction, to the north of Pax, the
^ e % sands often pass into calcareous sandstone, in
hich there are merely the casts of shells, as at Car-
res; and

°cks of recent origin which I have received from the

0ra l reefs of the Bermudas.

freshwater limestone at Saucats. — Associated with

e Miocene strata near Bordeaux, at a place called

u cats, is a compact freshwater limestone, of slight

into a shelly breccia, resembling some

thickn

ess, which is perforated on the upper surface by

arine shells, for the most part of extinct species.

ls evident that the ancient surface must at this

" a ce have been alternately occupied by salt and fresh

ter . The ground, perhaps, may have been alter*

te ly raised and depressed, or a lagoon may have been

/^ed, in which the water became fresh; then a bar-

er of sand, by which the sea was excluded for a

f ivy.

le 5 may have been breached, so that the salt water
a § a in obtained

x l* Dufrenoy has classed this freshwater limestone

"hocene (tertiaire superieur), but, from the fresh-

a ter shells contained in it, as well as from the marine

° Ssils °n which it rests and by which it is immediately

access.

v ol. iv.

122

MIOCENE PERIOD.

[Book JT-

cene. Among the shells determined by M. C. Des-
moulins, we find Cyrena Brongniarti, Bast., Planar*
bis rotundatas, and Limnea longiscata, species found
elsewhere in beds older than the Pliocene.*

basin

The rel

tions of some of the members of the tertiary series,
in the basin of the Gironde, have of late afforded
matter of controversy. A limestone, resembling the
calcaire grossier of Paris, and from one hundred to
two hundred feet in thickness, occurs at Pauliac and
Blaye, and extends on the right bank of the Gironde,
between Blaye and La Roche. It contains many species
of fossils identical with tho&e of the Paris basin- This
fact was pointed out to me by M. Deshayes before I
visited Blaye in 1830; but although I recognized the
mineral characters of the rock to bp very different
from those of the Miocene formations in the imme-
diate neighbourhood of Bordeaux, I had not time to
verify its relative position. ] inferred, however, the
inferiority of the Blaye limestone to the Miocene
strata, from the order in which each series presented
itself, as I receded from the chalk and passed to the
central parts of the Bordeaux basin.

Upon leaving the white chalk with flints, in travel-
ling from Charante by Blaye to Bordeaux, I first found
myself upon overlying red clay and sand (as at Mi-
rambeau) : I then came upon the tertiary limestone
above alluded to, at Blaye ; and lastly, on departing
still farther from the chalk, reached the strata which,
at Bordeaux and Dax, contain exclusively the Miocene
shells.

* See M. Dufrenoy's Paper, p, 341

■ ,

■ - .

, :

<*. XV. 3

BDRDEAUX BASIN.

123

of tertiary

roups

But

The occurrence both of Eocene and Miocene fossils

!l * the same basin of the Gironde, had been cited by

**• Boue as a fact which detracted from the value of

Zoological characters as a means of determining the

c hronological relations
arther inquiry, the Tact has been found to furnish

Additional grounds of confidence in these characters.

M. Ch. Desmoulins replied, to M. Boue's objections,
that the assemblage of Eocene shells are never inter-
mixed with those found in the " moellon/' as he calls
*ke sandy calcareous rock of the environs of Bordeaux
a ^d Dax; and M. Dufrenoy farther stated, that the
^lls of limestone which border the right bank of the
Fronde, from Marmande as far as Blaye, present
several sections wherein the Parisian (or Eocene)
^estone is seen to be separated from the shelly
str ata called " faluns," or " moellon," by a freshwater
0r *nation of considerable thickness. It appears, there-

re > that as the marine faluns of Touraine rest on a

r eshvvater formation, which overlies the marine cal-
^re grossier of Paris, so the marine Miocene strata
Q * Bordeaux are separated from those of Blaye by a

freshwater deposit.*

A he following diagram will express the order of
P°sition of the groups above alluded to.

Fig. 140.

*• R ed clay and sand.

imestone like calcaire grossier, sometimes
6 r een marl, and containing Eocene shells.

alternating with

Bulletin de la Soc. Geol. de France, tome ii. * d4n -

G 2

124

MIOCENE PERIOD.

[Book IV.

c. Freshwater formation, same as that of the department of Lot

and Garonne.
di Tertiary strata of the Landes, same as Fig. 139., with Miocene

fossils.

M. Dufrenoy considers the upper sands without fos-
sils, which cover the low flat countries of Medoc and
the Landes, to be of the age of the Subapennine beds. #
But there appears as yet to be scarcely sufficient data
to enable us to draw such an inference. It is, however,
clear that the true Subapennine or Older Pliocene
formation exists between Perpignan and the Pyre-
neesf ; so that in one region, in the south of France,
we have the Eocene, Miocene, and Pliocene form-
ations all represented : an important fact, as directly
opposed to the theory which endeavours to explain
away the distinctness of the fossils of different tertiary
groups, by supposing them to have been all deposited
in contemporaneous basins belonging to independent
zoological provinces, not in lakes and seas inhabited
successive!// by distinct species.

A few miles west from

Dax, and at the distance of about twelve miles from
the sea, a steep bank is seen running in a direction
nearly north-east and south-west, or parallel to the
contiguous coast. This steep declivity, which is about
fifty feet in height, conducts us from the higher plat-

Fig. 141..

Sea f

Section of Inland Cliff at Abesse, neir Dax.

&. Sand of the Landes.

6. Limestone.

c. Clay.

* See his paper above cited, tomeiii. p. 11.

i i r> r\

|3j2 a'jove, p. 69.

,■'

Ch. XV.]

INLAND CLIFF NEAR DAX.

125

form of the Landes to a lower plain which extends to
the sea. The outline of the ground might suggest to

rery geologist the opinion that the bank in question
^as once a sea-cliff, when the whole country stood at
a lower level relatively to the sea. But this can no
longer be regarded as matter of conjecture. In making
excavations recently for the foundation of a building at
Abesse, a quantity of loose sand, which formed the
slope de, was removed ; and a perpendicular cliff, about
fi % feet in height, which had hitherto been protected
from the agency of the elements, was exposed. The
bottom of this cliff consists of limestone b, which con-
tains tertiary shells and corals. Immediately below

e limestone is the clay, c ; and above it the usual
tertiary sand, a, of the department of the Landes. ^ At
tl^e base of the precipice are seen large partially
funded masses of rock, evidently detached from the
stratum b. The face of the limestone is hollowed out
a «d weathered into such forms as are seen in the cal-
careous cliffs of the adjoining coast, especially at
^iaritz, near Bayonne. It is evident that, when the
country was at a somewhat lower level, the sea ad-

v anced along the surface of the argillaceous stratum c,
w hich, from its yielding nature, favoured the waste by
Undermining the more solid superincumbent lime-
stone b. Afterwards, when the country had been
el evated, part of the sand, a, fell down, or was drifted
b y the winds, so as to form the talus, d e, which
tasked the inland cliff until it was artificially laid
°Pen to view.

The situation of this cliff is interesting, as marking
°oe of the pauses which intervened between the suc-
cessive movements of elevation by which the marme

g 3

■'"■

126

MIOCENE PERIOD.

[Book IV

tertiary strata of this country were upheaved to their
present height, a pause which allowed time for the
sea to advance and strip off the upper beds a, b, from
the denuded clay c.

Montpellier. -The tertiary strata of Montpellier con-
tain many of the Dax and Bordeaux species of shells,
so that they are probably referable to the Miocene
epoch ; but in the catalogue given by M. Marcel de
Serres, many Pliocene species, similar to those of the
Subapennine beds, are enumerated. M. de Christol

angustidens, Rhinoceros lepto-

mentions Ma

rhinus, a Tapir, a Palaeotherium, and an Anthracothe-
rium, together with many other mammifers, besides
cetacea and reptiles. *

It would be highly interesting if, upon fuller inves-
tigation, the Montpellier beds should be found to
indicate a passage from the fossils of the Miocene
type to those of the Older Pliocene. We may expect
the discovery of such intermediate links, and I have
endeavoured to provide a place for them in the chs-

Hills of Mont Ferrat

The late

Signer Bonelli of Turin was the first who remarked
that the tertiary shells found in the green sand and
marl of the Superga. near Turin differed, as a group,
from those generally characteristic of the Subapennine
beds. The same naturalist had also observed, that
many of the species peculiar to the Superga were
identical with those occurring near Bordeaux and
Dax. The strata of which the hill of the Superga is
composed are inclined at an angle of more than

* Resum°

de M. Boue, p. 128. Bull, de la Soc. G&l. de

France, torn, iii.

f Vol. Ill

^.XV.2 MONT FERRAT AND THE SUPERGA.

127

seventy degrees, as I found when I examined the

Murch

1828.

■I hey consist partly of fine sand and marl, and partly
G * a conglomerate composed of primary boulders,
w hich forms a lower part of the series, and not, as
re presented by M. Brongniart by mistake, an un-
conformable and overlying mass.* The same series of

0c cur in a bright green sand

err at, especially in the basin of the Bormida. The
high road which leads from Savona to Alessandria
intersects them in its northern descent, and the form-
a tion may be well studied along this line at Carcare,
^ a iro, and Spinto, at all which localities fossil shells

| At Piana, a conglo-
merate, interstratified with this green sand, contains
bounded blocks of serpentine and chlorite schist, larger
than those near the summit of the Superga, some of
*hetn being not less than nine feet in diameter.

When we descend to Aqui, we find the green sand

giving place to bluish marls, which also skirt the plains

°* the Tanaro at lower levels. These newer marls are

a ssociated with sand, and are nearly horizontal, and

appear to belong to the Older Pliocene Subapennine

str ata. f The shells which characterize the latter

Abound in various parts of the country near Turin; but

bat region has not yet been examined with sufficient

c are to enable us to give exact sections to illustrate

ttle superposition of the Miocene and Older Pliocene

e ^s. It is, however, ascertained, that the highly

nc hned green sand, which comes immediately in con-

ac t with the primary rocks, is the oldest part of the

series.

* Terrains du Vicentin, p. 26.
f See section, Fig. 84. Vol. Ill

G 4

p. 338.

128

MIOCENE PERIOD.

[Book IV.

Molasse of

If we cross the Alps

and pass from Piedmont to Savoy, we find there, at
the northern base of the great chain, and throughout
the lower country of Switzerland, a soft green sand-
stone much resembling some of the beds of the basin
,of the Bormida, above described, and associated in a

similar manner with marls and conglomerate. This
formation is called in Switzerland « molasse," said to
be derived from « mol," « soft? because the stone is
easily cut in the quarry. It is of vast thickness; but
shells have so rarely been found in it, that they do not
supply sufficient data for correctly determining its
age. M. Studer, in his treatise on the " molasse,"
enumerates some fossil shells found near Lucerne,
agreeing, apparently, with those of the Subapennine'
hills. The correspondence in mineral character be-
tween the green sand of Piedmont and that of Switzer-
land can in nowise authorise us to infer identity of
— but merely to conclude that both have been
derived from the degradation of similar ancient rocks.
Until the place of the « molasse " in the chrono-
logical series of tertiary formations has been more
rigorously determined, the application of this provincial
name to the tertiary groups of other countries must
be very uncertain, and it will be desirable to confine
it to the tertiary beds of Switzerland.

age,

Styria, Vienna, Hungary.

Of the various groups

which have hitherto been referred to the Miocene
era, none are so important in thickness and geogra-
phical extent as those which are found at the eastern
extremity of the Alps, in what have been termed the
basins of Vienna and Styria, and which spread thence
into the plains of Hungary. The collection of shells

Ch. XV.]

STYRIA — VIENNA —HUNGARY.

129

of Vienna, and described by him in 1820*, was alone
sufficient to identify a great part of the formations of
'hat country with the Miocene beds of the Loire,
^ironde^ and Piedmont. The fossil remains subse-
quently procured by that indefatigable observer M.
Boue have served to show the still greater range of
'he same beds through Hungary and Transylvania.
It appears from the recently published memoirs of

Profe

ssor Sedgwick and

Murchisonf

formations of Styria may be divided into groups cor-

Vienna beds ; the basin of Styria exhibiting nearly the
s ame phenomena as that of Vienna.

These regions

'wo deep bays of the same sea, separated from each
other by a great promontory connected with the cen-
tal ridge of the eastern Alps.

The English geologists above mentioned describe a
l°flg succession of marine strata intervening between
'he Alps and the plains of Hungary, which are divi-
s *ble into three natural groups, each of vast thickness,
an d affording a great variety of rocks.. All these
S r oups are of marine origin, and lie in nearly horizontal
str ata, but have throughout a slight easterly dip ; so
'hat, in traversing them from west to east, we com-
^ence with the oldest, and end with the youngest

heds.

At their western extremity they fill an irregular
' r ough-shaped depression, through which the waters
°f the Mur, the Raab, and the Drave, make their way
'° the lower Danube.^ Here the first group is de-

* Journal de Physique, Novembre, 1 820.

f Geol. Trans., Second Series, vol. iii. p. 301.

\ Ibid., p. 382.

G 5

; 1

■

•

130

MIOCENE PERIOD.

[Book IV,

veloped, consisting of conglomerate, sandstone, and
marls, some of the marls containing marine shells.
Beds also of lignite occur, showing that wood was
drifted down in large quantities into the sea. In parts
of the series there are masses of rounded siliceous
pebbles, resembling the shingle banks which are form-
ing on some of our coasts.

The second principal group is characterized by
coralline and concretionary limestone of a yellowish
white colour ; it is finely exposed in the escarpments

This coralline limestone is

not less than 400 feet thick at Wildon, and exceeds,
therefore, some of the most considerable of our se-
condary groups in England, f

Beds of sandstone, sand, and shale, and calcareous

marls, are associated with the above-mentioned lime-
stone.

The third group, which occurs at a still greater dis-
tance from the mountains, is composed of sandstone
and marl, and of beds of limestone, exhibiti

ing Here

and there a perfectly oolitic structure. In this system
fossil shells are numerous.

In regard to the age of the formations above de-
scribed, it is by no means clear that the coralline lime-
stones of the second group are posterior i

in origin to

all the beds of the first division ; they may possibly
have been formed at some distance from land, while
the head of the gulf was becoming filled up with
enormous deposits of gravel, sand, and mud, which
may, in that quarter, have rendered the waters too
turbid for the fullest development of testaceous and
coralline animals.

Geol. Trans., Second Series, vol. iii. p. 385. f Ibid, p. 390.

c h. XV. 3

STY RI A — VIENNA — HUNGARY.

131

The middle group, both in the basins of Styria and

■p.

Mio

J or the species of shells are the same as those of the
-^oire, Gironde, and other contemporary basins before
Noticed. Whether the lowest and uppermost systems
are referable to the same, or to distinct tertiary epochs,
ls the only question. We cannot doubt that the accu-
mulation of so vast a succession of beds required an
lr *imense lapse of ages, and we should expect to find
s °ftie difference in the species characterizing the differ-
en t members of the series ; nevertheless, all may be-
0n g to different subdivisions of the Miocene period.

Mr, Mur

'hat the inferior, or first group, which comprises the
str ata between the Alps and the coralline limestone of
^ildon, may correspond in age to the Paris basin ; but
delist of fossils which they have given seems rather
to favour the supposition that the deposit is of the
Miocene era. They mention four characteristic
Miocene fossils, — Mytilus Brardii, Cerithium pictum,
^- pupseforme, and C. plicatum :
e W-of the associated shells are common to the Paris

and though some

as *n, such a coincidence is no more than holds

regard to all the European Miocene form-

at ions.

On the other hand, the third or newest system,
w hich overlies the coralline limestone, contains fossil
^hirfi do not appear to depart so widely from the
-liocene type as to authorize us to separate them.
lle y appear to agree with the tertiary strata of a
§ re at part of Hungary and Transylvania, which are
deferable to the Miocene period.*

See tables of shells by M. Deshayes, in Appendix I. of the
<*tavo edition.

G 6

I t

132

MIOCENE PERIOD.

[Book IV.

Volhynia and Podolia . — We

strata; and there is already sufficient evidence that
the marine deposits of the platform of Volhynia and
Podolia were of this era. The fossils of that region,
which is bounded by Galicia on the west, and the
Ukraine on the east, and comprises parts of the basins
of the Bog and the Dneister, has been investigated by
Von Buch, Eichwald, and Du Bois ; and the latter has
given excellent plates of more than one hundred fossil

Mioce

The formation consists of sand and sandstone, clay,
coarse limestone, and a white oolite, the last of which
is of great extent.

Mayence. — The tertiary strata near Mayence con-
tain in abundance the Mytilus Brardii, and several other
characteristic Miocene fossils. They occupy a tract
from five to twelve miles in breadth, extending a lon<r
the left bank of the Rhine from Mayence to tl
bourhood of Manheim, and are again found to be east,
north, and south-west of Frankfort. In some places
they have the appearance of a freshwater formation ;
but in others, as at Alzey, the shells are for the most
part marine. Cerithia are in great profusion, which
indicates that the sea where the deposit was formed
was fed by rivers; and the great quantity of fossil land
shells, chiefly of the genus Helix, confirm th
opinion. The variety in the species of shells is small,
scarcely eighty having yet been discovered, as I learn
from Professor Bronn, of Heidelberg, while the indi-
viduals are exceedingly numerous; a fact which accords

* Conch. Foss. du Plateau Wolhyni-Podol., par F. du Bois.
Berlin, 1831.

e same

Ch. XV.]

1VI A YENCE — OSNABRUCH,

133

perfectly with the idea that the formation may have
originated in a gulf or sea which, like the Baltic, was
brackish in some parts and almost fresh in others. A
s pecies of Paludina, very nearly resembling the recent
^ttorina ulva, is found throughout this basin. These
shells may be compared in size to grains of rice, and
°*ten are in such quantity as to form almost entire
s *rata of marl and limestone. I have seen them as
thick as grains of sand, in stratified masses fifteen feet
thick ; and Professor Bronn has observed a succession
Q* beds thirty feet in thickness, of which they are the
Principal constituent.

I was unable to find any natural sections which ex-
hibited the relations of the Mayence strata above de-
scribed to the sandy beds of Eppelsheim, wherein the
fie\y g enus Deinotherium, and the bones of the Mas-
todon avernensis, and other mammifers, have been dis-
covered. But I think it most probable that they all

bel

ong to the same era, and that the freshwater beds

°t Georges Gemund, in Bavaria, as well as several
°ther detached lacustrine groups of that country and
°t Wurtemburg, may be referred to the Miocene period.
*^t Georges Gemund, as in Touraine, we find an asso-
Cla tion of the genera Palaeotherium, Mastodon, and

Rhinoceros.

Osnabruck. — From the fossils which I have seen in
l he cabinet of Count Munster at Bayreuth, I have little
do ubt that strata of the Miocene period are largely
developed between the mountains of the Teutobour-
Serwald and Wesergebirge, including the environs of
snabruch, Munster, Astrupp, and other places.

134

CHAPTER XVI.

i .

MIOCENE FORMATIONS

AXLUVIAL — FRESHWATER

VOLCANIC.

Miocene alluviums

Auvergne

drupeds — Velay — Orleanais

Mont Perrier — Extinct qua-
Alluviums contemporaneous

with Faluns of Touraine — Miocene freshwater formations-
Upper Val d'Arno — Extinct mammalia (p. 138.) — Coal of
Cadibona — Miocene volcanic rocks

vama

Styria

Auvergne

Velay.

Hungary — Transyl-

In the present chapter I shall offer some observations
on the alluviums and freshwater formations of the
Miocene era, and shall afterwards point out the coun-
tries in Europe where the volcanic rocks of the same
period may be studied.

Auvergne.

Miocene Alluviums.
The annexed drawing will

explain the

position of two ancient beds of alluvium, c and e in

Position of the Miocene alluviums of Mont Perrier (or Boulade).

Descending series.
Newer alluvium. bm Second trBchjtic breccIa ,

Second Miocene alluvium with bones.

d. First trachytic breccia.

e. First Miocene alluvium with bones

f. Compact basalt.

g. Eocene lacustrine strata.

Ch. XVI.]

AUVERGNE.

135

•^uvergne, in which the remains of several quadrupeds
characteristic of the Miocene period have been ob-
a med. In order to account for the situation of these
e ds of rounded pebbles and sand, we must suppose
*at after the tertiary strata g, covered by the basaltic
ava /> had been disturbed and exposed to aqueous
^nudation, a valley was excavated, wherein the allu-
Vl um e was accumulated, and in which the remains of
9 u adrupeds then inhabiting the country were buried.
*he trachytic breccia d was then superimposed; this
Dr eccia is an aggregate of shapeless and angular frag-
ments of trachyte, cemented by volcanic tuff and
pUrxiice, resembling some of the breccias which enter
lnt o the composition of the neighbouring extinct vol-
cano of Mont Dor in Auvergne 3 or those which are
*°und on Etna. Upon this rests another alluvium, c,
w Wch also contains the bones of Miocene species, and
^s is covered by another enormous mass of tufaceous
re ccia. The breccias have probably resulted from the
s Udden rush of large bodies of water down the sides of
ari elevated volcano at its moments of eruption, perhaps
v hen snow was melted by lava. Such floods occur in
celand, sweeping away loose blocks of lava and ejec-
ts surrounding the crater, and then strewing the
P*ains with fragments of igneous rocks, enveloped in

j**ud or " moya." The abrupt escarpment presented
y the above-described beds, b, c, d, e, towards the
alley of the Couze, must have been caused by subse-
quent erosion, which has carried away a large portion
of those masses.*

■for an account of the position and age of the volcanic brec-
as of Mont Perrier and Boulade, see Lyell and Murchison on
e Beds of Mont Terrier, Ed. New Phil. Journ., July, 1829,

136

MIOCEKE PERIOD.

[Book IV.

In the alluviums

Chabriol, and Bouillet have discovered the remains
of about forty species of extinct mammalia, the greater
part of which are peculiar as yet to this locality ; but
some of them are characteristic of the Miocene period,
being common to the faluns of Touraine, and asso-

• , i • . » it.. ._

Miocene

Mastodon

minor and M. arvernensis, Hippopotamus major,
Rhinoceros leptorhinus, and Tapir arvernensis. The
Elephas primigenius, a species common to so many
tertiary periods, is also stated to accompany the rest.
In some cases the remains are not sufficiently charac-
teristic to indicate the exact species, but the follow-
ing genera can be determined : — The boar, horse, ox,

hyaena (

), felis (th

or four), bear
, otter, beaver,

(three), deer (many species)
hare, and water-rat.*

Velay. — In Velay a somewhat similar group of
mammiferous remains were found by Dr. Hibbert t
in a bed of volcanic scoriae and tuff, inclosed between
two beds of basaltic lava, at Saint Privat d'Allier.
Some of the bones were found adhering to the slaggy
lava. Among the animals were Rhinoceros lepto-
rhinus, Hyaena spelaea, and another species allied to
the spotted hyaena of the Cape, together with four
undetermined species of deer, t

At Cussac and Solilhac, one league from Puy en

* Recherches sur les Oss. Foss. du Dept. du Puy de Dome,
4to. 1828. Essai Geol. et Mineral, sur les Environs d'Issoire
Dept. du Puy de Dome, folio, 1827.

•f Edin. Journ. of Sci., No. iv. New Series, p. 276.

$ Figures of some of these remains are given by M. Bertrand
de Doue, Ann. de la Soc. d'Agricult. de Puy, 1828.

C1 >- XVI.]

UPPER VAL D' ARNO.

137

covered with lava, the remains of Elephas primigenius,

Hhi

(

(seven species)

an antelope.

Orfeanais. — In the Orleanais, at Avaray, Chevilly,
les Aides, and les Barres, fossil land quadrupeds have
)e en found associated with fluviatile shells and rep-
lies 5 identical with those found in the marine faluns
°* Touraine. * These are supposed with great pro-
bability, by M. Desnoyers, to mark the passage of

str eams which flowed towards the sea in which the
a *uns were deposited.

Miocene Freshwater Formations.

Upper Void Arno. — There are a great number of
| s °lated tertiary formations, bf freshwater origin, rest-
In § on primary and secondary rocks in different parts
of: Europe, in the same manner as we now find small
a{< es scattered over our continents and islands, wherein
^Posits are forming, quite detached from all contem-
porary marine strata. To determine the age of such
§ r ° u ps, with reference to the great chronological
Ser ies established for the marine strata, must often be
a Matter of difficulty, since we cannot always enjoy an
°Pportunity of studying a locality where the fresh-
water species are intermixed with marine shells, or

w here they occur in beds alternating with marine
st rata.

The deposit of the Upper Val d' Arno before alluded

* MM. Desnoyers and Lockart, Bulletin de la Soc. G£ol.,
tom - u. p. 336.

138

MIOCENE PERIOD.

[Book AT.

but, although the fossil testaceous and mammiferous
remains preserved therein are very numerous, it is
scarcely possible, at present, to decide with certainty
the precise era to which they belong. I collected
six. species of lacustrine shells, in an excellent state
of preservation, from this basin, belonging to the ge-

was

unable to identify any one of them with any
recent or fossil species known to him. If the beds
belonged to the Older Pliocene formations, we might
expect that several of the fossils would agree specifi-
cally with living testacea ; and I am therefore disposed
to believe that they belong to an older epoch. If we
consider the terrestrial mammilla of the same beds,
we immediately perceive that they cannot be assimi-
lated to the Eocene type, as exhibited in the Paris
basin, or m Auyergne and Velay : but some of them

s P ecIes - Mr. Pentland has

agree with Mi

obligingly sent me the following list of the
mammifers of the upper Val d'Arno which are in the

fossil

museums of Paris.

erce

Ursus cultridens, Vi-

(?)

size of the common fox. Hyaana radiata, H. fossilis

dentia
Pad

(a new species, of the size of the panther)

Histrix nearly a n ied to d^saiu/caston

Mastodon ansrusti-

scrota, Khmoceros lentorh.nno w

- . ' „ . ^Pwinmus, Hippopotamus ma ]or,

dens, M. Taperoides, Tapir

■» Equu

fossilis. Ruminantia

darnensis, C.

B. urus and B. taurus.

(new species)

(?)

Cuvier also mentions the remains of a species of
lophiodon as occurring among the bones in the Upper

Ch - XVI.]

Val d'Ar

CADIBONA.

139

no. * The elephant of this place has been

considered by
snecies E. vri-

^genius, with which, however, some eminent com-
P a ^ative anatomists regard it as identical. The skele-
tons of the hippopotamus are exceedingly abundant ;

n0 less than forty had been
procured when I visited Flo-
rence in 1828. Remains of

QJ
QJ

68
CO

o #}

£n

*
SO

£ O

C4H

r- 1

{-I

C5
CO

O-.

the elephant, stag, ox, and
horse, are also extremely nu-
merous. In winter the super-
ficial degradation of the soil
is so rapid, that bones which
| the year before were buried
are seen to project from the
surface of the soil, and are
described by the peasants as
growing. In this manner the
tips of the horns of stags, or
of the tusks of hippopota-
muses, often appear on the
surface, and thus lead to the
discovery of an entire head

D {

O
QJ
O
c5

c3 .^
63

or skeleton.
Cadibona.

Another ex-
ample of an isolated lacus-
trine deposit, belonging pos-
sibly to the Miocene period,
is that which occurs at Cadi-
0n a> between Savona and Carcare ; a place which I

°ss. Foss., vol. v. p. 504.
t Lettere sopraalcune Ossa Fossili del Val d'Arno, &c. Pisa,

^25.

■

140

MIOCENE PERIOD.

[Book Tf>

Mr. Mu

son. Its position is described in the annexed section,
which does not, however, pretend to accuracy in regard
to the relative heights of the different rocks, or the
distances of the places from each other. The lacus-
trine strata are composed of gravel, grit, and micaceous
sandstone, of such materials as were derivable from
the surrounding primary rocks; and so great is the
thickness of this mass, that some valleys intersect it
to the depth of seven or eight hundred feet without
penetrating to the subjacent formations. In one part
of the series, carbonaceous shales occur, and several
seams of coal from two to six feet in thickness ; but
no impressions of plants of which the species could be
determined, and no shells have been discovered. Many
entire jaws and other bones of an extinct mammifer,
called by Cuvier Anthracotherium, have been found
m the coal-beds, the bone being itself changed into a
kind of coal ; but as this species has not as yet oc-
curred elsewhere in association with organic remains of
known date, it affords us no aid when we attempt to
assign a place to the lignites of Cadibona.

Miocene Volcanic Bocks.

Hungary -M. Beudant, in his elaborate work on
Hungary, describes five distinct groups of volcanic
rocks, which, although nowhere of great extent, form
striking features in the physical geography of that
country, rising as they do abruptly from extensive
plains composed of tertiary strata. They may have
constituted islands in the ancient sea, as Santorin and
Milo now do in the Grecian Archipelago • and M Beu-

Ch.XVl.]

VOLCANIC ROCKS — HUNGARY.

141

jlant has remarked that the mineral products of the

as t-mentioned islands resemble remarkably those of

le Hungarian extinct volcanos, where many of the

an *e minerals, as opal, calcedony, resinous silex (silex

Tesin ite), pearlite, obsidian, and pitchstone abound.

( *he Hungarian lavas are chiefly felspathic, con-

*sting of different varieties of trachyte ; many are

eJ *ular, and used as millstones ; some so porous and

% Ve n scoriform as to resemble those which have issued

** the open air. Pumice occurs in great quantity ; and

° er e are conglomerates, or rather breccias, wherein

ra gments of trachyte are bound together by pumiceous

u ^j or sometimes by silex.

It is probable that these rocks were permeated by

^ e waters of hot springs, impregnated, like the Gey-

Sers > with silica ; or, in some instances, perhaps, by

j^ous vapours, which, like those of Lancerote, may

av e precipitated hydrate of silica. *

■ky the influence of such springs or vapours the
p Unks and branches of trees washed down during
°°ds, and buried in tuffs on the flanks of the moun-
ain s, may have become silicified. It is scarcely pos-
lb *e, says M. Beudant, to dig into any of the pumiceous
e posits of these mountains without meeting with
Prized wood, and sometimes entire silicified trunks
r trees of great size and weight.
m ^ appears from the species of shells collected prin-
cipally by M. Boue, and examined by M. Deshayes,
at the fossil remains imbedded in the volcanic tuffs
p in strata alternating with them in Hungary, are
the Miocene type, and not identical, as was formerly
8u Pposed, with the fossils of the Paris basin.

* See Vol. II. p. 142

■

142

MIOCENE PERIOD.

[Book Vt

Transylvania. — The igneous rocks of the eastern
part of Transylvania, described by M. Boue, are pro-
bably of the same age. They cover a considerable
area, and bear a close resemblance to the Hungarian
lavas, being chiefly trachytic. Several large craters,

Maar

are met with in some regions ; and a rent in the tra-
chytic mountains of Budoshagy exhales hot sulphureous
vapours, which convert the trachyte into alum-stone;
a change which that rock has undergone at remote
periods in several parts of Hungary.

Styria — Many of the volcanic groups of this country
bear a similar relation to the Styrian tertiary deposits,
as do the Hungarian rocks to the marine strata of that
country. The shells are found imbedded in the vol-

■

canic tuffs in such a manner as to show that they lived
in the sea when the volcanic eruptions were in progress,
as many of the Val di Noto lavas in Sicily, before de-
scribed, were shown to be contemporaneous with the
Newer Pliocene strata. *

Auvergne— Velay.—l believe that part of the volca-
nic eruptions of Auvergne took place during the Mio-
cene period ; those, for example, which cover, or are
interstratified with, the alluviums mentioned in this
chapter, and some of the ancient basaltic cappings of
hills in Auvergne, which repose on gravel characterized
by similar organic remains. A part also of the igneous
rocks of Velay must belong to this epoch ; but these

will be again referred to when I treat

fully of

the volcanic rocks of Central France, the older part of
which are referable to the Eocene period.

* Sedgwick and Murchison, Geol. Trans., Second Series, rol.iii
p. 400. Daubeny's Volcanos, p. 92.

143

fr v

CHAPTER XVII.

EOCENE FRESHWATER FORMATIONS.

cene period — Freshwater formations — Central France
-Limagne d'Auvergne— - Sandstone and conglomerate

Tra-

Map
Ter~
lar y red marl and red sandstone — Green and white foliated
ln arls (p. 149.) — Indusial limestone — Gypseous marls
Ve Uin — Freshwater formation of Puy en Velay (p. 157.)
^ Cantal — Resemblance of Aurillac limestone and flints to
° Ur upper chalk - — Concluding remarks.

fi have now traced back the history of the European
, Nations to that period when the seas and lakes were

lla bited by testacea, of which a few only belonged
, s pecies now existing ; a period which I have de-
boated Eocene, as indicatir

But although a small

a * e of the animate creation.

. lrTl ber only of the living species of animals were then

being, there are ample grounds for inferring that all

e great classes of the animal kingdom, such as they

w exist, were then fully represented. In regard to

e ^stacea, indeed, it is no longer a matter of infer-
ence

I for more than 1200 species of this class have

er * obtained from that small number of detached

. ° c ene deposits which have hitherto been examined
lri Europe.

A »e celebrated Paris basin, the position of which

^as

(

)

;

■

144

EOCENE PERIOD.

[Book

IV.

seems to claim our chief attention when we examine
the phenomena of this era. But in order the more
easily to explain the peculiar nature and origin of that
group, it will be desirable, first, to give a brief sketch
of certain deposits of Central France, which afford
many interesting points of analogy to that of Paris,
both in organic remains and mineral composition, and
where the original circumstances under which the
strata were accumulated may more easily be dis-
cerned.

Auvergne. — The deposits alluded to, which I ex-
amined in the summer of 1828, in company with Mr.
Murchison, are those of the lacustrine basins of Au-
vergne, Cantal, and Velay, and their sites may be
seen in the annexed map. They appear to be the mo-
numents of ancient lakes, which may have resembled
in geographical distribution some of those now existing
in Switzerland, and may like them have occupied the
depressions in a mountainous country, and have been
each fed by one or more rivers and torrents. The
country where they occur is almost entirely composed
of granite and different varieties of granitic schist, with
here and there a few patches of secondary strata much
dislocated, and which have probably suffered great de-
nudation. There are also some vast piles of volcanic
matter (see the map), the greater part of which is
newer than the freshwater strata, and is sometimes
seen to rest upon them, whilst a small part has evi-
dently been of contemporaneous origin. Of these
igneous rocks I shall treat more particularly in the
nineteenth chapter, and shall now speak only of the
lacustrine beds.

The most northern of the freshwater groups is situ-
ated in the valley-plain of the Allier, which lies within

146

EOCENE PERIOD.

[Book IV

the department of the Puy de Dome, being the tract
which went formerly by the name of the Limagne
d'Auvergne. It is inclosed by two parallel primitive
ranges, — that of the Forez, which divides the waters
of the Loire and Allier, on the east; and that of the
Monts Domes, which separates the Allier from the
Sioule, on the west.* The average breadth of this
tract is about twenty miles ; and it is for the most part
composed of nearly horizontal strata of sand, sandstone,
calcareous marl, clay, and limestone, none of which
observe a fixed and invariable order of superposition.
The ancient borders of the lake wherein the fresh-
water strata were accumulated, may generally be
traced with precision, the granite and other ancient
rocks rising up boldly from the level country. The
precise junction, however, of the lacustrine and granitic
beds is rarely seen, as a small valley usually intervenes

between them. The freshwater strata may sometimes
be seen to retain their horizontality within a very

slight distance of the border-rocks, while in

some

places they are inclined, and in a few instances ver-
tical. The principal divisions into which the lacus-
trine series may be separated are the following:
1st, Sandstone, grit, and conglomerate, including red

2dly, Green and white

arl

d red sandstone.

foliated marls. 3dly, Limestone or travertin, oolite-
4thly, Gypseous marls.

1. a. Sandstone and conglomerate. — Strata of sand
and gravel, sometimes bound together into a solid rock

are

found in great abundance around the confines of
the lacustrine basin, containing, in different places?
pebbles of all the ancient rocks of the adjoining ele-
vated country; namely, granite, gneiss, mica-schist?

* Scrope, Geology of Central France, p. 15.

•

Cl >. XVII.]

LACUSTRINE STRATA— AUVERGNE.

(

c *ay-slate, porphyry, and others. But the arenaceous
s ^ata do not form one continuous band around the
jtoargin of the basin, being rather disposed like the
independent deltas which grow at the mouths of tor-
r ^nts along the borders of existing lakes.*

At Chamalieres, near Clermont, we have an ex-
arn ple of one of these littoral groups of local extent,
^here the pebbly beds slope away from the granite as
** they had formed a talus beneath the waters of the
lake near the steep shore. A section of about fifty
* e et in vertical height has been laid open by a torrent,
an d the pebbles are seen to consist throughout of
r °unded and angular fragments of granite, quartz, pri-
mary slate, and red sandstone ; but without any inter-
mixture of those volcanic rocks which now abound

ln the neighbourhood. Partial layers of lignite and
Pteces of wood are found in these beds, but no shells ;
a fact which probably indicates that testacea could
**°t live where the turbid waters of a stream were

e quently hurrying down uprooted trees, together
^ Vl th sand and pebbles, or that, if they existed, they
^ere triturated by the transported rocks.

There are other localities on the margin of the basin
^here quartzose grits are found, composed of white
s and bound together by a siliceous cement.

Occasionally, when the grits rest on granite, as at
Chamalieres before mentioned, and many other places,
t * le separate crystals of quartz, mica, and felspar, of
l ^e disintegrated granite, are bound together again by
the silex, so that the granite seems regenerated in a
^ e w and even more solid form ; and thus so gradual a
Passage may easily be traced between a crystalline

See book ii. chap. v.

H 2

148

EOCENE PERIOD,

<■ I

[Book IV.

rock and one of mechanical origin, that we can scarcely
distinguish where one ends and the other begins.

In the Puy de Jussat, and the neighbouring hill of
La Roche, are white quartzose grits, cemented by
calcareous matter, which is sometimes so abundant as
to form imbedded nodules. These sometimes consti-
tute spheroidal concretions six feet in diameter, and
pass into beds of solid limestone resembling the Italian
travertins, or the deposits of mineral springs.

In the hills above mentioned, we have the advan-
tage of seeing a section continuously exposed for about
seven hundred feet in thickness. At the bottom are
foliated marls, white and green, about four hundred
feet thick; and above, resting on the marls, are the
quartzose grits before mentioned, with the associated
travertins. This section is close to the confines of the
basin ; so that the lake must here have been filled up
near the shore with fine mud, before the coarse super-
incumbent sand was introduced. There are other
cases where sand is seen below the marl.

1. b. Red marl and sandstone. — But the most re-
markable of the arenaceous groups is one of red sand-
stone and red marl, which are identical in all their
characters with the secondary new red sandstone and
marl of England. In these secondary rocks, the red
ground is sometimes variegated with light greenish
spots, and the same may be seen in the tertiary form-
ation of freshwater origin at Coudes, on the Allien
The marls are sometimes of a purplish-red colour, as
at Champheix, and are accompanied by a reddish lime-
stone like the well-known « cornstone," which is asso-
ciated with the old red sandstone of English geologists.
The red sandstone and marl of Auvergne have evi-
dently been derived from the degradation of gneiss

fc #1

Cil. XVII.3

LACUSTRINE STRATA - AUVERGNE.

149

f n d mica-schist, which are seen in situ on the adjoin -

n g hills, decomposing into a soil very similar to the

ertiary red sand and marl. We also find pebbles of

* eis s, mica-schist, and quartz, in the coarser sand-

0Q es of this group, clearly pointing to the parent

ocks from which the sand and marl were derived.

e red beds, although destitute themselves of organic
* ei *ains, pass upwards into strata containing Eocene
0s sils, and are certainly an integral part of the lacus-

trine formation.

white foliated

A great portion

°* what we term clay in ordinary language consists of
fte same materials as sand, but the component parts
are in a finer state of subdivision. The same primary
r °cks, therefore, of Auvergne which, by the partial
de gradation of their harder parts, gave rise to the
^artzose grits and conglomerates before mentioned,
vv °uld, by the reduction of the same materials into
Powder, and by the decomposition of their felspar,
m *ca, and hornblende, produce aluminous clay ; and, if
a sufficient quantity of carbonate of lime was present,
calcareous marl. This fine sediment would naturally
e carried out to a greater distance from the shore, as
ar e the various finer marls now deposited in Lake
Superior.* And, as in the American lake, shingle and
s and are annually amassed near the northern shores,
So in Auvergne the grits and conglomerates before
Mentioned were evidently formed near the borders.
t The entire thickness of these marls is unknown ; but
* l certainly exceeds, in some places, seven hundred
ee t- They are for the most part either light-green
or white, and usually calcareous. They are thinly

* See Vol. I. p. 344.

H 3

150

EOCENE PERIOD.

[Book IV.

foliated, — a character which frequently arises from the
innumerable thin plates or scales of that small animal
called Cypris; a genus which comprises several species,
of which some are recent, and may be seen swimming
swiftly through the waters of our stagnant pools and
ditches. The antennae, at the end of which are fine

Fig. 145.

Fig. 146

Cypris unifasciata, a living species, greatly

magnified.

Cypris vidua, a living species
greatly magnified.*

a. Upper part. b. Side view of the same.

pencils of hair, are the principal organs for swimming,
and are moved with great rapidity. This animal re-
sides within two small valves not unlike those of a
bivalve shell, and moults its integuments annually,
which the conchiferous mollusks do not. This cir-
cumstance may partly explain the countless myriads
of the shells of cypris which were shed in the Eocene
lakes, so as to give rise to divisions in the marl as thin
as paper, and that too in stratified masses several
hundred feet thick. A more convincing proof of the
tranquillity and clearness of the waters, and of the
slow and gradual process by which the lake was filled
up with fine mud, cannot be desired. But we may

-
i

* See Desmarest's Crustacea, plate 55

Ch - XVII.] LACUSTRINE STRATA — AUVERGNE.

151

easily suppose that, while this fine sediment was
thrown down in the deep and central parts of the
basin, gravel, sand, and rocky fragments were hurried
ir ^to the lake near the shore, and formed the group
described in the preceding section.

Not far from Clermont, the green marls, containing
the cypris in abundance, approach to within a few yards

Fig. 147

Vertical strata of marl near Clermont

A- Granite. B. Space of sixty feet, in which no section is seen.
C« Green marl, vertical and inclined. D. White marl.

°f the granite which forms the borders of the basin.
The annexed section occurs at Champradelle, in a
small ravine north of La petite Baraque, and above
the bridge.

The occurrence of these marls so near the ancient
Margin may be explained by considering that, at the
bottom of the ancient lake, no coarse ingredients were
deposited in spaces intermediate between the points
^here rivers and torrents entered, but finer mud only
w as drifted there by currents. The verticality of some
°f the beds in the above section bears testimony to
considerable local disturbance subsequent to the de-
position of the marls ; but such inclined and vertical

strata are very rare.

3. Limestone, travertin, oolite.— Both the preceding
m embers of the lacustrine deposit, the marls and grits*

152

EOCENE PERIOD.

[Book IV.

pass occasionally into limestone. Sometimes only
concretionary nodules abound in them ; but these,
where there is an increase in the quantity of cal-

regular beds.

imagne

the west at Gannat, and on the east at Vichy, a white
oolitic hmestone is quarried. At Vichy, the oolite
resembles our Bath stone in appearance and beauty,
and, hke it, is soft when first taken from the quarry,
but soon hardens on exposure to the air. At Gannat,
the stone contains land-shells and bones of quadru-
peds, resembling those of the Paris gypsum. In
several places in the neighbourhood of Gannat, at

surface.*
Indusial limestone.

Marc

— „»„, «mi »wuc is uiviueu dv lavers

of clay. J J

At Chadrat, in the hill of La Serre, the limestone is
pisohtic, and m this and other respects resembles the
travertin of Tivoli. It presents the same combination
of a radiated and concentric structure, and the coats
of the different spheroids have the same undulating

, c „ . ,, There is another remarkable

form of freshwater limestone in Auvergne, called
"indusial, from the cases, or indusice, of the larva, of
Phryganea, great heaps of which have been incrusted,
as they lay, by carbonate of lime, and formed int0 ,
hard travertin. Several beds of this rock, either in
continuous masses or in concretionary nodules, are
seen superimposed one upon another, with layers of
marl interposed. We may often observe in our ponds
some of the living species of this kind of insect, covered

* See Fig. 1 2. Vol. I. p. 323.

■KT

Ch. XVIL]

LACUSTRINE STRATA _ AUVERGNE.

153

w *th small freshwater shells, which they have the
Power of fixing to the outside of their tubular cases, in
or der, probably, to give them weight and strength.

J—^Trill^^ --;*„ ~ T, «<r— t ,*S"" -*— ^ 35 ^W^..

■^ , — - - fT*Wx<

w*^,,

Fig. 148. r f he individual figured in

the annexed cut, which be-
longs to a species very abun-
dant in England, has hap-
pened to cover its case
with shells of a small Plan-
In the same manner a large species which
farmed in the Eocene lakes of Auvergne was accus-
tomed to attach to its dwelling the shells of a small

ZL~-^-j

• *Mf*- "~ u

Larva of recent Phryganea.*

orbis.

tire

r al univalve of the genus Paludina. A hundred of
se minute shells are sometimes seen arranged
ar ound one tube, part of the central cavity of which is
of ten empty, the rest being filled up with thin concen-
tri c layers of travertin. The cases have been thrown
to gether confusedly, and often lie, as in Fig. 149., at
ri ght angles one to the other. When we consider
ha t ten or twelve tubes are packed within the com-
Pass of a cubic inch, and that some single strata of this
lr *iestone are six feet thick, and may be traced over a

tier

149.

a. Indusial limestone of Auvergne.
6. Fossil Paludina magnified.

I beli

leve that the British specimen here figured is P. rhom

lca > Linn.

H 5

154

EOCENE PERIOD.

[Book TV.

considerable area, we may form some idea of the count-
less number of insects and mollusca which contributed
their integuments and shells to compose this singularly
constructed rock. It is unnecessary to suppose that
the Phryganeae lived on the spots where their cases
are now found ; they may have multiplied in the shal-
lows near the margin of the lake, or in the streams by
which it was fed, and their buoyant cases may have
been drifted by a current far into the deep water.*

The calcareous strata of the Limagne, like the other
members of this lacustrine formation, are for the most
part horizontal, or inclined at a very slight angle, but
instances of local dislocation are sometimes observable.
At the town of Vichy, for example, in an ancient
quarry behind the convent of Celestines, the strata
dip at an angle of between thirty and forty degrees ;
and near the hot spring at the same place, the beds
of limestone are seen, in one part of the section, in-
clined at an angle of eighty degrees, and in another
vertical.

4. Gypseous marls — More than fifty feet of thinly
laminated gypseous marls, exactly resembling those in
the hill of Montmartre, at Paris, are worked for gypsum
at St. Romain, on the right bank of the Allier. They
rest on a series of green cypriferous marls which
alternate with grit, the united thickness of this inferior
group being seen, in a vertical section on the banks of
the river, to exceed 250 feet.

General arrangement and origin of the freshwater
formations of Auvergne. — The relations of the different
groups above described cannot be learnt by the study

* For remarks on the floating of empty land shells by rivers,
see above, p. 33., and Vol. III. p. 360.

Ch. XVII.] LACUSTRINE STRATA 1 - AUVERGNE.

155

of any one section, and the geologist who sets out with
the expectation of finding a fixed order of succession
m ay perhaps complain that the different parts of the
basin give contradictory results. The arenaceous
^vision (l.p.H6.), the marls (2. p. 149.), and the
limestone (3. p. 151.), may all be seen in some places
to alternate with each other ; yet it can by no means
" e affirmed that there is no order of arrangement. The
Sa nds, sandstone, and conglomerate, constitute in ge-
neral a littoral group ; the foliated white and green
^arls, a contemporaneous central deposit ; and the
limestone is for the most part subordinate to the
ttewer portions of both. The uppermost marls and
s ands are more calcareous than the lower; and we
never meet with calcareous rocks covered by a con-
siderable thickness of quartzose sand or green marl.
From the resemblance of the Eocene limestones of
Auvergne to the Italian travertins, we may conclude
that they were derived from the waters of mineral

springs,

such springs as now exist in Auvergne, and

w hich, rising up through the granite, precipitate tra-
v ertin. They are sometimes thermal, but this cha-
racter is by no means constant.

It seems that, when the ancient lake of the Li-
m agne first began to be filled with sediment, no vol-
c anic action had yet produced lava and scoriae on any
Part of the surface of Auvergne. No pebbles, there-
fore, of lava were transported into the lake,
fragments of volcanic rocks imbedded in the conglo-
merate. But at a later period, when a considerable

tiiickn

ess

of sandstone and marl had accumulated,

er uptions broke out, and lava and tuff were deposited,
a t some spots, alternately with the lacustrine strata,
^oofs of this will be given in the 19th chapter. It is

h 6

I
I

156

EOCENE PERIOD.

[Book IV

not improbable that cold and thermal springs, holding
different mineral ingredients in solution, became more
numerous during the successive convulsions attending
this development of volcanic agency, and thus deposits
of carbonate and sulphate of lime, silex, and other
minerals were produced. Hence these minerals pre-
dominate in the uppermost strata. The subterranean
movements may then have continued until they altered
the relative levels of the country, and caused the waters
of the lakes to be drained off, and the farther accumu-
lation of regular freshwater strata to cease. The oc-
currence of these convulsions anterior to the Miocene
epoch, and their continuance during a succession o*
after-ages, may explain why no freshwater formations
more recent than the Eocene are now found in this

country.

We may easily conceive a similar series of events
to give rise to analogous results in any modern basin,
such as that of Lake 1 Superior, for example, where
numerous rivers and torrents are carrying down the
detritus of a chain of mountains into the lake. The
transported materials must be arranged according to
their size and weight, the coarser near the shore, the
finer at a greater distance from land; but

in the
gravelly and sandy beds of Lake Superior no pebbles
of modern volcanic rocks can be included, since there
are none of these at present in the district. If igneous
action should break but in that country and produce
lava, scoriae, and thermal springs, the deposition of
gravel, sand, and marl might still continue as before ;
but in addition, there would then be an intermixture
of volcanic gravel and tuff, and of rocks precipitated
from the waters of mineral springs.

Although the freshwater strata of the Limagne ap-

Ch. XVII.] LACUSTRINE STRATA — PUY EN VELAY.

157

P r oach generally to a horizontal position, the proofs of
ocal disturbance are sufficiently numerous and violent
allow us to suppose great changes of level since the

Eocene period. We are unable to assign a northern

carrier to the ancient lake, although we can still trace
lts limits to the east, west, and south, where they were

0r nied of bold granitic eminences. But we need not
" e surprised at our inability to restore the physical
geography of the country after so great a series of

°lcanic eruptions ; for it is by no means improbable

that

one part of it may have been moved upwards

bodily, while others remained at rest, or even suffered
a Movement of depression.

Puy en Velay. — In the department of the Haute
^°ire, a freshwater formation, very analogous to that
°f Auvergne, is situated in the basin of the Loire, and
is exposed in the valley in which stands the town of
^ e Puy. Since the deposition of the lacustrine strata,

^ere have been so many volcanic eruptions in this
c °Untry, and such immense quantities of lava and
s coriae have been poured out upon the surface, that

** e aqueous rocks are almost buried and concealed.
■**ut we are indebted co the researches of M. Bertrand

deD

oue, for having distinctly ascertained the succes-

sion of strata, and I have myself had opportunities of
e *ifying his observations during a visit to Le Puy.

■hi this basin we find, as in Auvergne, two great
Visions, consisting of grits and marls ; the former
c °ttiposed of quartzose grit, in some places resembling
§ r anite, and of reddish and mottled sands and conglo-
merates. All these were evidently derived from the
degradation of granitic rocks, and are very like the
^"enaceous group of the Limagne before described.
f hey are almost confined to the borders of the basin,

158

EOCENE PERIOD.

[Book I V.

and were evidently a littoral deposit. The other
member of the formation, the marls, are more or less
calcareous, and are associated with limestone and
gypsum, which last exactly resembles that of Paris,
and is worked for agricultural uses.

The analogy in the mineral charater of the Velay
and £aris basins is rendered more complete by the
presence in both of silex in regular beds. In the
limestone I found gyrogonites, or seeds of the Chara,
of the same species as those most common in the
Paris basin ; and M. Bertrand de Doue has discovered
the bones of several mammiferous animals of the same
genera as those which characterize the basins of Au-
vergne and Paris.* The species of shells also of this
formation are the same as those of Eocene formations

in other parts of France.

The sand and conglomerate of the freshwater basin
of Velay are entirely free from volcanic pebbles, agree-
ing in this respect with the analogous group of the
Limagne ; but the fact is the more striking in Velay.
because the masses of trachyte, clinkstone, and other
igneous rocks now abounding in that country, have an
aspect of very high antiquity, and constitute a most
prominent feature in the geological structure of the
district. Yet the non-intermixture of volcanic pro-
ducts with the lacustrine sediment, is just what we
should expect when we have ascertained that the im-
bedded organic remains of those strata are Eocene ;
whereas the lavas belong in part, if not entirely, to the
Miocene period.-)-

Cantal — Near Aurillac, in Cantal, another series
of freshwater strata occurs, which resembles, in mi-

* Descrip. Geognos. des En v. du Puy en Velay, 1823.
f See p. 136., and chap. xix.

Ch - XVII.]

LACUSTRINE STRATA - CANTAL.

159

er al character and organic remains, those of Auvergne
an d Velay already described. The leading feature of

hls group, as distinguished from the two former, is

ne immense abundance of silex associated with the
calcareous marls and limestone, which last constitute,

lk e the limestone of Auvergne, an upper member of
ltle freshwater series.

Cantal

* the

groups, the lower composed of gravel, sand, and
cla y> such as might have been derived from the wear-
n g down and decomposition of the granitic schists of
he surrounding country ; the upper system, consisting
°* siliceous and calcareous marls, contains subordin-
ate^ gypsum, silex, and limestone — deposits such as
**e waters of springs charged with carbonate and sul-
phate of lime, and with silica, may have produced.
Freshwater limestone and fl\

, ° the English geologist, the most interesting feature

Cantal is the resemblance of the freshwater
lr ttestone, and its accompanying flint, to our upper
°halk ; a resemblance which (like that of the red sand-
st °ne of Auvergne to our secondary " new red") is
^ e more important, as being calculated to put the
st udent upon his guard against relying too implicitly
0tl Hthological characters as tests of the relative ages
r ocks. When we approach Aurillac from the west,

e pass over great heathy plains, where the sterile
^ca-schist is barely covered with vegetation. Near
* tr ac, and between La Capelle and Viscamp, we find

116 surface strewed over with loose broken flints, some
ot them black in the interior, but with a white externa)

others stained with tints of yellow and red,

bating ;

atl d in appearan
c halk districts.

precisely like the flint gravel of our

! i

^^^^

160

EOCENE PERIOD.

[Book

iV.

announced our approach to a new formation, we arrive
at length at the escarpment of the lacustrine beds. A*
the bottom of the hill which rises before us, we see
strata of clay and sand resting on mica-schist ; and
above, in the quarries of Belbet, Leybros, and Bruel,
a white limestone, in horizontal strata, the surface of
which has been hollowed out into irregular furrows,
since filled up with broken flint, marl, and dark vege-
table mould. In these cavities we recognize an exact
counterpart to those which are so numerous on the
furrowed surface of our own white chalk. Advancing
from these quarries, along a road made of the white
limestone, which reflects as glaring a light in the sun,
as do our roads composed of chalk, we reach, at length,
in the neighbourhood of Aurillac, hills of limestone and
calcareous marl, in horizontal strata, separated in some

places by regular layers of flint in nodules, the coat-
ing of each nodule being of an opaque white colour,
like the exterior of the flinty nodules of our chalk-
This hard white substance has been ascertained in
England to consist, in some instances, wholly 6f sili-
ceous matter, and sometimes to contain a small admix-
ture of carbonate of lime *, an d the analysis of the
similar rocks in the Cantal would probably give the
same results. The Aurillac flints have precisely the
appearance of having separated from their matrix after
the siliceous and calcareous matter had been blended
together. The calcareous marl sometimes occupies
small sinuous cavities in the flint ; and the siliceous
nodule, when detached, i s often as irregular in form as
those found in our chalk.

Phillips, Geol. Trans., First Series, vol. v. p. 22. — Outlines

of Geology, p. 95.

CJ >. XVI L]

LACUSTRINE STRATA — CANTAL,

16!

By what means, then, can the geologist at once
decide that the limestone and silex of Aurillac are
re ferable to an epoch entirely distinct from that of
the English chalk ? It is not by reference to position ;
tor we can merely say of the lacustrine beds, as we
s hould have been able to declare of the true chalk had
xt been present, that they overlie the granitic rocks of
hls part of France. It is from the organic remains
° n 'y that we are able to pronounce the formation to

belon

g to the Eocene tertiary period. Instead of the

Marine Alcyonia of our cretaceous system, the silici-
^ e d seed-vessels of the Chara, a plant which grows at
t * le bottom of lakes, abound in the flints of Aurillac,

both

in those which are in situ and those forming the

S^vel. Instead of the Echini and marine testacea of
** e chalk, we find in these marls and limestones the

shell

s of the Planorbis, and other lacustrine testacea,

| °f them, like the gyrogonites, agreeing specifically

*ith

species of the Eocene type.

Some

Proofs of the gradual deposition of marl.
e ctions of the foliated marls in the valley of the Cer,
ear Aurillac, attest, in the most unequivocal manner,
ne extreme slowness with which the materials of the
aeu strine series were amassed. In the hill of Barrat,
^ example, we find an assemblage of calcareous and

^ceous marls, in which, for a depth of at least sixty

et > the layers are so thin that thirty are sometimes

Stained in the thickness of an inch ; and when they

e separated we see preserved in every one of them

< e flattened stems of Charse, or other plants, or some-

^es myriads of small paludince and other freshwater

e us. These minute foliations of the marl resemble

j: Wisely some of the recent laminated beds of the
c °tch marl lakes, and may be compared to the pages

162

EOCENE PERIOD.

[Book IV.

of a book, each containing a history of a certain period
of the past. The different layers may be grouped
together in beds from a foot to a foot and a half i n
thickness, which are distinguished by differences of
composition and colour, the tints being white, green,
and brown. Occasionally there is a parting layer of
pure flint, or of black carbonaceous vegetable matter,
about an inch thick, or of white pulverulent marl.
We find several hills in the neighbourhood of Aurillac
composed of such materials for the height of more
than 200 feet from their base, the whole sometimes

covered by rocky currents of trachytic or basaltic
lava. *

Thus wonderfully minute are the separate parts
of which some of the most massive geological monu-
ments are made up ! When we desire to classify*
it is necessary to contemplate entire groups of strata
in the aggregate; but if we wish to understand
the mode of their formation, and to explain their
origin, we must think only of the minute

subdi-
visions of which each mass is composed. We must
bear in mind how many thin leaf like seams of matter,
each containing the remains of myriads of testacea
and plants, frequently enter into the composition of a
single stratum, and how vast a succession of these
strata unite to form a single group ! We must re-
member also, that volcanos like the Plomb du Cantal
which rises in the immediate neighbourhood of Au-
rillac, are themselves equally the result of succes-
sive accumulation, consisting of reiterated flows of
lava and showers of scoriae ; and I have shown, when

* Lyell and Murehison, sur les Depots Lacust. Tertiaires d*
Cantal, &c. Ann. des Sci. Nat., Oct. 1829.

Ch - XVII.] LACUSTRINE STRATA - CANTAL.

163

^eating of the high antiquity of Etna, how many dis-
tin ct lava-currents and heaps of ejected substances
are required to make up one of the numerous conical

env elopes whereof a volcano is composed.

Lastly,

We must not forget that continents and mountain-
clla ins, colossal as are their dimensions, are nothing
""ore than an assemblage of many such igneous and
a< lUeous groups, formed in succession during an

definite lapse of ages, and superimposed upon each

oth

er.

164

CHAPTER XVIII

EOCENE FORMATIONS

PARIS BASIN.

Marine Eocene strata — Paris basin how far analogous to deposit*
of Central France — Connexion of Auvergne and Paris basins
— Groups in Paris basin— Observations of M. C. Prevost—
Contemporaneous marine and freshwater strata — Abundant

of Cerithia (p. 169.)
Parisian groups Eocene
of quadrupeds in gypsum

Upper marine formation

All the
Bone*

Microscopic shells (p. 176.)-

Strata with and without organic

knowledge

of the

remains alternating _ Extent of our ^

physical geography, fauna, and flora of the Eocene period
Concluding remarks.

The geologist who has studied the lacustrine form-
ations described in the last chapter cannot enter the
tract usually termed « the Paris Basin " without im-
mediately recognizing a great variety of rocks with
which his eye has already become familiar. The green
and white marls of Auvergne, Cantal, and Velay,
again present themselves, together with limestones and
quartzose grits, siliceous and gypseous marls, nodules
and layers of flint, and saccharoid gypsum ; lastly, in
addition to all this identity of mineral character, he
finds an assemblage of the same species of fossil ani-
mals and plants.

When we consider the geographical proximity oi
the two districts, we are the more prepared to ascribe
this correspondence in the mineral composition <&
these groups to a combination of similar circumstances

Ch.

XVHL]

PARIS BASIN

165

*tth

e same era. From the map (Fig. 144. p. 145.) in

e last chapter, it will be seen that the united waters

tfie Allier and Loire, after descending from the

le ys occupied by the freshwater formations of

' er *tral France, flow on till they reach the southern

e *tremity of what is called the Paris basin. M. Oma-

s d'Halloy long ago suggested the very natural idea

at there existed formerly a chain of lakes, reaching

*** the highest part of the central mountain-group

France, and terminating in the basin of Paris, which

Su pposes was at that time an arm of the sea.

t Notwithstanding the great changes which the phy-

c al geography of this part of France must since have

*^ er gone, we may easily conceive that many of the

pritl cipal features in the configuration of the country

*y have remained unchanged, or but slightly modified.

s of volcanic matter have indeed been formed since

e E

ocene formations were accumulated, and the

e *s of large tracts have been altered in relation to

s ^a ; lakes have been drained, and a gulf of the

turned into dry land, but many of the reciprocal

ations of the different parts of the surface may still

^ ai n the same. The waters which flowed from the

ni tic heights into the Eocene lakes may now

, Ce nd in the same manner through valleys once the

-tts of those lakes. Let us, for illustration, suppose

tl t great Canadian lakes, and the gulf into which

, Ir Waters are discharged, to be elevated and laid

^ b y subterranean movements. The whole hydro-

, Phical basin of the St. Lawrence might be upraised

n g these convulsions, yet that river might continue,

11 after so extraordinary a revolution, to drain the

e elevated regions, and might still convey its

ers in the same direction from the interior of the

•

1 •

166 EOCENE PERIOD. [Book 1 V '

continent to the Atlantic. Instead of traversing the
lakes, it would hold its course through deposits ot
lacustrine sand and shelly marl, such as we know to b e
now forming in Lakes Superior and Erie ; and these
freshwater strata would occupy the site, and bea*
testimony to the pristine existence of the lakes. M^
rine strata may also be brought into view in the spa° e
where an inlet of the sea, like the estuary of the S^
Lawrence, had once received the continental waters 5
and in such formations we might discover shells ot
lacustrine and fluviatile species intermingled with
marine testacea and zoophytes.

Subdivisions of strata in the Paris basin.— The are* 1
which has been called the Paris basin is about 1 8 °
miles in its greatest length from north-east to south-
west, and about ninety miles from east to west. Th lS
space may be described as a depression in the chal*
(see Fig. 82. Vol. III. p. 332.), which has been filled up
by alternating groups of marine and freshwater strata
MM. Cuvier and Brongniart attempted in 1811 to dis*
tinguish five different formations, and to arrange the** 1
in the following order, beginning with the lowest:

_. r , . f Plastic clay.
1. First freshwater! T . J

1 . i Lignite.

formation ^ F irst sandstone .

2. First marine form- 1 ~ . .
. r J- Calcaire grossier.

ation J

~ c j c ~„u«~„* f Siliceous limestone.

3. Second freshwater I G with bones of anima i s .
formation [ Freshwater marls.

& -i • f Gypseous marine marls.

4. Second marine I T /^ . a a a ^nps,

< Upper marine sands and sandstones

formation ^ Upper marine marls and ii mes tones.

ml _. j A, rt i, 4 f Siliceous millstone, without shells.
5 . Third freshwater I Siliceous millstone , with shells,
formation ^ Upper freshwater mar i s .

Ch .'XVin.]

PARIS BASIN.

167

These formations were supposed to have been de-
Posited in succession upon the chalk ; and it was
imagined that the waters of the ocean had been by
tur ns admitted into and excluded from the same

gion. But the subsequent investigations of several
geologists, especially of M. Constant Prevost *, have
le d to great modifications in the theoretical views en-
ter tained respecting the order in which the several
§ r °ups were formed ; and it now appears that the form-
ati °ns Nos. 1, % and 3. of the table of MM. Cuvier and
Br °ngniart, instead of having originated one after the
ot her, are divisible into four nearly contemporaneous
§ r oup s .

position of different formations in the Paris

A comparison of the two accompanying dia-

^ams will show at a glance the different relations

a $in.

% Brongniart.

Fig. 151.
M. Constant Prevost.

O- Upvur Freshwater

4- - Upper M.ari/u;

zdcz

]

Cede, Sil.

(*yps. Sec

Cole. Gros .

1. JPlastic Claif

c halfr

Chalk

Bulletin des Sci. de la Soc. Philom., May, 1825, p. 74

(

168

EOCENE PERIOD.

[Book

which the several sets of strata bear to each other,
according to the original as well as the more modern
classification. I shall now proceed to lay before the
reader a brief sketch of the several sets of strata re-
ferred to in the above systems.

Immediately upon the chalk a layer of broken chalfc
flints, often cemented into a breccia by siliceous sand,
is very commonly found. These flints probably indi-
cate the action of the sea upon reefs of chalk when a
portion of that rock had emerged, and before the
regular tertiary beds were superimposed. To this
partial layer no reference is made in the annexed
sections.

Plastic clay and sand. — Upon this flinty stratum*
or, if it be wanting, upon the chalk itself, rests fre-
quently a deposit of clay and lignite (No. 1. of the
above tables). It includes the remains of freshwater
shells and drift-wood, and was, at first, regarded as a
proof that the Paris basin had originally been filled
with fresh water. But it has since been shown that
this group is not only of very partial extent, but is by
no means restricted to a fixed place in the series ; for

)

(N-

that limestone at Veaugirard, Bagneux, and other
places, where the same Planorbes, Paludinae, and Lim-
neae occur. * M. Desnoyers pointed out to me a sec-
tion in the suburbs of Paris, laid open in 1829, where
a similar intercalation was seen in a still higher part
of the calcaire grossier. These observations relieve U*
from the difficulty of seeking a cause why vegetable
matter, and certain species of freshwater shells and a

* Prevost, Sur les Submersions Iteratives, &c. Mem. de 1»
Soc. d'Hist. Nat. de Paris, tome iv. p. 74.

* Ch XVIIL]

PARIS BASIN.

169

The calcaire grossiei

bove al-

Particular kind of clay, were at first introduced into
e basin, and why the same space was subsequently
burped by the sea. A minute examination of the phe-
nomena leads us simply to infer, that a river charged
!th argillaceous sediment entered a bay of the sea
nd drifted into it, from time to time, freshwater shell
an d wood.

Calcaire grossier

U(J ed to, is a coarse limestone, often passing into sand,

|* c « as may perhaps have been in part derived from

e aqueous degradation of a chalk country. It con-

ain s by far the greater number of the fossil shells

mch characterize the Paris basin. No less than 400

ls tinct species have been procured from a single spot

e ar Grignon. They are imbedded in a calcareous

an d, chiefly formed of comminuted shells, in which,

ev ertheless, individuals in a perfect state of preserv-

. l0 n, both of marine, terrestrial, and freshwater spe-

les > are mingled together, and were evidently trans-

j/ rted from a distance. Some of the marine shells

^ a y have lived on the spot ; but the Cyclostoma and

ln inea must have been brought thither by rivers and

c Urr ents, and the quantity of triturated shells implies

ns iderable movement in the waters.

Nothi

(li

fos

ing is more

striking

, . _ ^ m this assemblage of

* Sl1 testacea than the great proportion of species

erable to the genus Cerithium.

er e occur no less than one hundred and thirty-seven

(See fig. 152.)

g t — ~ «..«.. v,.w *.v*»uiuu cum urn ^-OCVCH

°f tt! es of this genus in the Paris basin? and almost a11

^ h em in the calcaire grossier. Now the living tes-
*iy €a 0f this S en us inhabit the sea near the mouths of

ab^' Wllere the waters are brackish, so that their
Undance in the marine strata of the Paris basin is in
e ct harmony with the hypothesis before advanced,

^o L ,

IV.

; : !

^■^^■^H

■>

170

£j

OCEXE PERIOD.

[Book

it-

Pig. 152.

that a river flowed into the gulf, and gave rise
to the beds of clav and lignite before me 11 "
tioned. But there are ample data for infe r *
ring that the gulf was supplied with &e sl
water by more than one river ; for while tn
alcaire grossier occupies the northern p& r
of the Paris basin, another contemporaneous
deposit, of freshwater origin, appears at tb^
southern extremity.

Calcaire siliceux. — This group (No, 3. ° '
the foregoing tables) is a compact siliceous
limestone, which resembles a precipitate fro***

the waters of mineral springs. It is often W

i Cerithium . . . .

cinctmn. * versed by small empty sinuous cavities ,
for the most part devoid of organic remains, but * IT
some places contains freshwater and land specif
and never any marine fossils. The siliceous lim e '
stone and the calcaire grossier occupy distinct parts o
the basin, the one attaining its fullest development ll
those places where the other is of slight thickness
They also alternate with each other towards the centra
of the basin, as at Sergy and Osny ; and there are eve**
points where the two rocks are so blended together
that portions of each may be seen in hand specimen^
Thus in the same bed, at Triel, we have the compa c
freshwater limestone, characterized by its lAv$se& 9
mingled with the coarse marine limestone throng
which the small multilocular shell, called miliiolite, 1&
dispersed in countless numbers. These microscop 1
testacea are also accompanied by Cerithia and othe
shells of the calcaire grossier. It is very extraordinary
that in this instance both kinds of sediment must b aV
been thrown down together on the same spot, ar>

* This snecies is found also in the Paris and London bastf* 5 *

Ch. XVIII.]

PARIS BASIN.

171

ea cn has still retained its own peculiar organic remains

t) °th m $# w a t Triel, and in hand specimens in his
cabinet.

These facts lead irresistibly to the conclusion, that
wll *le to the north, where the bay was probably open
the sea, a marine limestone was formed, another

e posit of freshwater origin was introduced to th

southward, or at the head of the bay; for it appears
lla t during the Eocene period, as now, the ocean was

the north ; and the continent, where the great lakes
exi sted, to the south. From that southern region we
111 a y suppose a body of fresh water to have descended
charged with carbonate of lime and silica, the water

r\ m

ein g perhaps in sufficient volume to convert the upper
en d of the bay into fresh water, like some of the gulfs
of the Baltic.

Gypsum and marls. — The next group to be con-
quered is the gypsum, and the white and green marls,
Subdivisions of No. 3. of the table of Cuvier and

r °ngniart. These were once supposed to be entirely
s ^bsequent in origin to the two groups already con-
quered ; but M. Prevost has pointed out that in some

° Ca lities they alternate repeatedly with the calcaire

1 lc eux, and in others with some of the upper mem-

ers of the calcaire grossier. The gypsum, with its

Ss °ciated marl and limestone, is in greatest force

° w ards the centre of the basin, where the two groups

ef ore mentioned are less fully developed ; and M.

rev ost infers, that while those two principal deposits

ere gradually in progress, the one towards the north,

a the other towards the south, a river descending

m the east may have brought down the gypseous

nc * marly sediment.

i 2

172

EOCENE PERIOD.

{[Book iV-

It must be admitted, as highly probable, that a bay
or narrow sea, 180 miles in length, would receive, at
more points than one, the waters of the adjoining
continent ; at the same time I may observe, that if the
gypsum and associated green and white marls of
Montmartre were derived from a hydrographical basin
distinct from that of the southern chain of lakes before
adverted to, this basin must nevertheless have been
placed under circumstances extremely similar; for the
identity of the rocks of Velay and Auvergne with the
freshwater group of Montmartre, is such as can scarcely
be appreciated by geologists who have not carefully
examined the structure of both these countries.

Some readers may think that the view above given
of the arrangement of four different sets of strata i n
the Paris basin is far more obscure and complicated
than that first presented to them in the system of
MM. Cuvier and Brongniart. Undoubtedly the rela-
tions of the several groups are less simple than the
first observers supposed, being much more analogous
to those before described in the lacustrine deposits
of Central France. The simultaneous deposition of
two or more groups of strata in one basin, some of
them freshwater and others marine, must always pro-
duce very complex results ; but in proportion as it &
more difficult in these cases to discover any fixed
order of superposition in the associated mineral masses?
so also is it more easy to explain the manner of then*
origin, and to reconcile their relations to the agency °*
known causes. Instead of the successive irruptions
and retreats of the sea, and changes in the chernicd
nature of the fluid and other speculations of the earlier
geologists, we are now simply called upon to imagin e
a gulf, into one- extremity of which the sea entered*

Ch - XVIII.]

PARIS BASIN,

173

an d at the other a large river, while other streams may
uave flowed in at different points, whereby an inde-
finite number of alternations of marine and freshwater
beds would be occasioned.

Second or Upper marine group* — The next group,

Ca 'led the second or uppe

)

^hich alternate with the freshwater beds of gypsum
an d marl last described. Above this division the pro-
ducts of the sea exclusively predominate, the beds
uemg chiefly formed of micaceous and quartzose sand,
ei ghty feet or more in thickness, surmounted by beds
°f sandstone, with scarcely any limestone. The sum-
^ts of a great many platforms and hills in the Paris
basin consist of this upper marine series.

I fully agree with M. C. Prevost that the alternation

°* the various marine and freshwater formations before

^scribed admit of a satisfactory explanation without

apposing different retreats and subsequent returns

°* the sea ; yet I think that a subsidence of the soil

v °uld best account for the position of these upper

ine sands. Oscillations of level may have oc-

Cl *rred, in consequence of which the sea and a river

^ a y have prevailed each in their turn for a time, until

1 length, by a more considerable sinking down of part

the basin, a tract previously occupied by fresh

a ter was converted into a sea of moderate depth.

£* one part of the Paris basin there are decisive

P r °ofs that during the Eocene period, and before the

Pper marine sand was formed, parts of the calcaire

sier were exposed to the action of denuding

es. At Valmondois, for example, a deposit of the

^ari

gros
c au s

u Pper

marine sandstone is found, in which rolled
lo cks of the calcaire grossier with its peculiar fossils,

i 3

(

174

EOCENE PERIOD.

[Book IV.

and fragments of a limestone resembling the calcaire
siliceux, occur.* These calcareous boulders are rolled
and pierced by perforating shells belonging to no less
than fifteen distinct species. Both the blocks and
many worn shells washed out from the calcaire gros-
sier, are found mingled with the ordinary fossils of the
upper marine sand.

We have seen that the same earthquake in Cutcb
could raise one part of the delta of the Indus and
depress another, and cause the river to cut a passage
through the upraised strata, and carry down the mate-
rials removed from the new channel into the sea. AU
these changes, therefore, might happen within a short
interval of time between the deposition of two sets of
strata in the same delta.f

It is not improbable, then, that the same convul-
sions which caused one part of the Paris basin to sink
down, so as to let in the sea upon the area previously
covered by gypsum and freshwater marl, may have
lifted up the calcaire grossier and the siliceous lime-
stone, so that they might be acted upon by the waves
and fragments of them swept down into the contiguous
sea, there to be drilled by boring testacea.

It is observed that the older marine formation at
Laon is now raised three hundred metres or nearly
one thousand feet above the sea, whereas the upper
marine sands never attain half that elevation. Such
may possibly have been the relative altitude of the
two groups when the newest of them was deposited.

* M. Deshayes, Memoires de la Soc. d'Hist. Nat. de Pari^
torn. i. p. 243. The sandstone is there called, by mistake, g r ^
marin inferieur, instead of superieur, to which last the author ha*
since ascertained it to belong.

f Vol. II. p. 194.

}

•'

Ch - XVIII.]

PARIS BASIN.

175

freshwater fi

sider another formation, the third freshwater group
(No. 5. of the preceding tables). It consists of marls
in terstratified with beds of flint and layers of flinty
n odul es . One set of siliceous layers is destitute of
0r ganic remains, the other replete with them.

Gyrogonites, or fossil seed-vessels of charge, are
f °und abundantly in these strata ; and all the animal
and vegetable remains agree well with the hypothesis,
tn at after the gulf or estuary had been silted up with
l he sand of the upper marine formation, a great number
of marshes and shallow lakes existed, like those which
frequently overspread the newest parts of a delta.
These lakes were fed by rivers or springs which con-
tained, in chemical solution or mechanical suspension,
s uch kinds of sediment as we have already seen to
have been deposited in the lakes of Central France
during the Eocene period.

The Parisian groups all Eocene.— Having now given
a rapid sketch >f the different groups of the Paris
hasin, I may observe generally that they all belong
to the Eocene epoch, although the entire series must
doubtless have required an immense lapse of ages for
*fe accumulation. The shells of the different fresh-
w ater groups, constituting at once some of the lowest
an d uppermost members of the series, are nearly all
deferable to the same species, and the discordance
between the marine testacea of the calcaire grossier
an d the upper marine sands is very inconsiderable.

A curious observation has been made by M. Des-
hayes, in reference to the changes which one species,
the Cardium porulosum, has undergone during the long
Period of its existence in the Paris basin. Different
v arieties of this cardium are characteristic of different

111

■

tarn

ir i

176

EOCENE PERIOD.

[Book IV.

strata. In the older sand of the Soissonais (a marine
formation underlying the regular beds of the calcaire

)

a small volume, and

•

Fig. 1 52. Jp

Cardium porulosum

Paris and London basins.

has many peculiarities, which disappear in the lowest
beds of the calcaire grossier. In these the shell attains
its full size, and many peculiarities of form, which are
again modified in the uppermost beds of the calcaire

grossier; and these last characters are preserve
throughout the whole of the " upper marine" series.*

Milioh

In some

parts of the calcaire grossier round Paris, certain
beds occur of a stone used in building, and called by
the French geologists miliolite limestone. It is almost
entirely made up of millions of small shells of the size
of minute grains of sand, which all belong to the same
class, but are of distinct species from those found in
the Older Pliocene beds of Italy. These minute fossil
bodies consist of multilocular shells, which were for-
merly referred to the order Cephalopoda, by M-
D'Orbigny, but M. Dujardin has shown that some of
them do certainly not belong to that order. They
were separated by D'Orbigny from the nautilus and
ammonite, by their having no siphon or internal tube
connecting the different chambers, and were called by
him Foraminifera. They are often in an excellent

* Coquilles caracterist. des Terrains, 1831

■ ■'

■

» ■

*:-\

---.

■ .

■'■.-.•..

k ■

■

^©

r -

■ i

I ■

■

> - * * *\ - '

• / , ♦ > * - - ■

. 1 *

i' ;

■

•

■

■ L

■

•*-•-?

'■

* ,v

- .■ 7.i.

;

: .

Ki <

.•^;*Vv"-v-

■

*A V

"••'I-./i-J*

■

. "

■

">,-

'-•-.

«J IN

-x

-5

«0

r^^N

■.

•3

■ -

CSi

■ I

r ~-H

■

'^J

VCs ^

* ±

—

■

Ch -XVIIL] MAMMIFEROUS REMAINS IN GYPSUM.

177

tete of preservation, and their forms are singularly
Cerent from those of the larger testacea.
A plate of some of these is given, from unpublished
Swings by M. Deshayes, who has carefully selected
116 most remarkable types of form. The natural size
e ach species figured (Plate XIII.) is indicated by

8u ch minute points, that it is necessary to call atten-

l °n to them, as they might otherwise be overlooked.

1 should also be mentioned that the genus miliolite of

^ftiarck has since been subdivided into several genera,

J^ong which are the Triloculina and Quifiqueloculina

Wd in the plate (PI. XIII.).

Characteristic shells. — The species of shells figured
ln the annexed plate are common in the Paris basin,
ar *d i^ a y b e considered as characteristic of the Eocene

Period

generally.

They appear as yet to be exclu-

Slv ely confined to deposits of that period, and are for
^ e most part abundant in them wherever they have
be en attentively studied. (PI XIV.)

~&o?ies of quadrupeds in gypsum. — I have already

c °ttsidered the position of the gypsum which occurs in

^ e form of a saccharoid rock in the hill of Mont-

^artre at Paris, and other central parts of the basin.

^ the base of that hill it is seen distinctly to alternate

Vl th soft marly beds of the calcaire grossier, in which

Cer ithia and other marine shells occur. But the great

^ a ss of gypsum may be considered as a purely fresh-

^ter deposit,, containing land and fluviatile shells,

°§ether with fragments of palm-wood, and great

Ut *ibers of skeletons of quadrupeds and birds, an

s semblage of organic remains which has given great

ee lebrity to the Paris basin. The bones of freshwater

®h,. also, and of crocodiles, and many land and fluvia-

e reptiles, occur in this rock. The skeletons of raara-

i 5

til

178

EOCENE PERIOD.

[Book IV

malia are usually isolated, often entire, the most deli-
cate extremities being preserved, as if the carcasses,

clothed with their flesh and skin, had been floated
down soon after death, and while they were still swoln
by the gases generated by their first decomposition-
The few accompanying shells are of those light kinds
which frequently float on the surface of rivers together
with wood.

■6S

have swept away the bodies of animals, and the plants
which lived on its borders, or in the lakes which i*
traversed, and may have carried them down into the
centre of the gulf into which flowed the waters im-
pregnated with sulphate of lime. We know that the
Fiume Salso in Sicily enters the sea so charged with
various salts that the thirsty cattle refuse to drink of
it. A stream of sulphureous water, as white as milk?
descends into the sea from the volcanic mountain of
Idienne, on the east of Java ; and a great body of hot
water, charged with sulphuric acid, rushed down from
the same volcano on one occasion, and inundated a
large tract of country, destroying, by its noxious pro-
perties, all the vegetation.* In like manner the P«"
sanibio, or " Vinegar River," of Colombia, which rises
at the foot of Purace, an extinct volcano, 7500 feet
above the level of the sea, is strongly impregnated
with sulphuric and muriatic acids, and with oxide of

We may easily suppose the waters of such
streams to have properties noxious to marine animals*
and in this manner the entire absence of marine re-
mains in the ossiferous gypsum may be explained.!

• Leyde Magaz. voor Wetensch Konst en Lett., partie *•
cahier i. p. 71. Cited by Rozet, Journ. de Geologie, torn. i. p.. 4&

* M..C Provost, Submersions Iteratives, &c. Note 23.

iron.

Ci) - XVIIIJ MAMMIFEROUS REMAINS IN GYPSUM.

179

There are no pebbles or coarse sand in the gypsum ;
a circumstance which agrees well with the hypothesis

h&t these beds were precipitated from water holding

Su lphate of lime in solution, and floating the remains

v0t different animals. The bones of land quadrupeds,

However, are not confined entirely to the freshwater

Or ftiation to which the gypsum belongs; for the re-
gains of a Palasotherium, together with some fresh-

a ter shells, have been found in a marine stratum be-

]
°ttging to the calcaire grossier at Beauchamp.

In the gypsum the remains of about fifty species of
quadrupeds have been found, all extinct, and nearly
four-fifths of them belonging to a division of the order
^achydermata, which is now represented by only four
* l ving species ; namely, three tapirs and the daman of
*he Cape. With them a few carnivorous animals are
as sociated, among which are a species of fox and gen-
^t. Of the Rodentia, a dormouse and a squirrel ; of
^e Insectivora, a bat ; and of the Marsupialia (an
°rder now confined to America, Australia, and some
Contiguous islands), an opossum, have been discovered.

Of birds, about ten species have been ascertained,
***e skeletons of some of which are entire. None of

em are referable to existing species.^ The same

re naark applies to the fish, according to MM. Cuvier
***d Agassiz, as also to the reptiles. Among the last
ar e crocodiles and tortoises of the genera Emys and
^ionix.

The tribe of land quadrupeds most abundant in this

0r ttiation is such as now inhabits alluvial plains and

Marshes and the banks of rivers and lakes, a class most

* Cuvier, Oss. Foss., torn. iii. p. 255

i 6

B ii

180

EOCENE PERIOD.

[Book

IV.

exposed to suffer by river inundations. Whether the
disproportion of carnivorous animals can be ascribed
to this cause, or whether they were comparatively
small in number and dimensions, as in the indigenous
fauna of Australia, when first known to Europeans, * s
a point on which it would be rash, perhaps, to offer an
opinion in the present state of our knowledge.
, We have no reason to be surprised that all the
species of vertebrated animals hitherto observed are
extinct, when we recollect that out of 1122 species of
fossil testacea obtained from the Paris basin, thirty*
eight only can be identified with species now living*
I have more than once adverted to the fact, that ex-
tinct mammalia are often found associated with assent
blages of recent shells, a fact from which I have inferred
the inferior duration of species of the mammalia as com-
pared with the testacea ; and it is not improbable that
the higher order of animals in general may more readily
become extinct than the marine mollusca. Some of
the thirty-eight species of testacea above alluded Uh
as having survived from the Eocene period to our own
times, have now a wide geographical range, as, for ex-
ample, Lucina divaricata*, and are therefore fitted to
exist under a great variety of circumstances. On the
other hand, the great proportion of the Eocene marine
testacea which have become extinct sufficiently de-
monstrates that the loss of species has been due to
general laws ; and that a sudden catastrophe, such as
the invasion of a whole continent by the sea
which could annihilate only the terrestrial and fresh-
water tribes, — is an hypothesis wholly inadequate to
account for the phenomenon.

a cause

See Fig. 85. Vol. III. p. 372,

Ch -XVlII.l

CONCLUDING REMARKS.

181

Strata with and without organic remains alternating.

Between the gypsum of the Paris basin and the
u Pper marine sands a thin bed of oysters is found,
^hich is spread over a remarkably wide area. From
the manner in which they lie, it is inferred that they
*hd not grow on the spot, but that some current swept
them away from a bed of oysters formed in some other
P a *'t of the bay. The strata of sand which immediately
r epose on the oyster-bed are quite destitute of organic
r emains ; and nothing is more common in the Paris ba-
Slr * and in other formations, than alternations of shelly
"eds with others entirely devoid of them. The tempo-
ra *y extinction and renewal of animal life at successive
Periods have been inferred from such phenomena,
^hich may nevertheless be explained, as M. Prevost
Justly remarks, without appealing to any such extra-
ordinary revolutions in the state of the animate cre-
ation. A current one day scoops out a channel in a
^d of shelly sand and mud, and the next day, by a
s hght alteration of its course, ceases to prey upon the
Sa me bank. It may then become charged with sand
^ttttrixed with shells, derived from some dune, or
fought down by a river. In the course of ages an
^definite number of transitions from shelly strata to
those without shells may thus be caused.

Concluding remarks. — It will be seen by our ob-
servations on Auvergne and other parts of Central
France, and on the district round Paris, that geologists
have already gained a considerable insight into the
st ate of the physical geography of part of Europe during
the Eocene period. We can point to some districts
^here lakes and rivers then existed, and to the site of
So *ne of the lands encircling those lakes, and to the po-
s *tion of a great bay of the sea, into which their surplus

182

EOCENE PERIOD.

[Book

IV.

waters were discharged. We can also show, as I shall
endeavour to explain in the next chapter, the points
where some volcanic eruptions took place. Much
information has been acquired respecting the quadru-
peds which inhabited the land at that period, and con-
cerning the reptiles, fishes, and testacea which swarmed
in the waters of lakes and rivers ; and we have a col-
lection of the marine Eocene shells more complete
than has yet been obtained from any existing sea of
equal extent in Europe- Nor are the contemporary
fossil plants altogether unknown to us, which, like
the animals, are of extinct species, and indicate &
warmer climate than that now prevailing in the same
latitudes.

When we reflect on the tranquil state of the earth?
implied by some of the lacustrine and marine deposits
of this age, and consider the fulness of all the different
classes of the animal kingdom, as deduced from the
study of the fossil remains, we are naturally led to
conclude, that the earth was at that period in a per-
fectly settled state, and already fitted for the habitation
of man.

The heat of European latitudes during the Eocene
period does not seem to have been superior, if eqbal?
to that now experienced between the tropics ; some
living species of molluscous animals, both of the land,
the lake, and the sea, existed when the strata of the
Paris basin were formed ; and the contrast in the or-
ganization of the various tribes of Eocene i animals?
when compared to those now co-existing with man?
although striking, is not, perhaps, so great as between
the living Australian and European types. At the
same time, we must be fully aware that we cannot
reason with any confidence on the capability of our

Ch - XVIII.]

CONCLUDING REMARKS.

183

°^n, or any other contemporary species, to exist under
Clr cumstances so different as those which might be
c ^used by an entirely new distribution of land and sea;
ai *d we know that in the earlier tertiary periods the
Physical geography of the northern hemisphere was
Ver y distinct. Our inability to account for the atmo-
s pheric and other latent causes, which often give rise
to the most destructive epidemics, proves the extent
°t our ignorance of the entire assemblage of conditions
re quisite for the existence of any one species on the
lobe.

184

CHAPTER XIX.

EOCENE VOLCANIC ROCKS.

Train of minor volcanos stretching from Auvergn e

Volcanic rocks of Auvergne — Eruptions at successive periods
Mont Dor an extinct volcano — Velay — Plomb du Cantal
(p. 191.)

to the Vivarais — Monts Domes — Ravines excavated through
lava — Alluviums of distinct ages (p. 195.)
modern lavas of Central France — No eruption during them 9-
torical era — Division of volcanos into ante-diluvian and post-
diluvian inadmissible — Theories respecting the effects of the
Flood considered (p. 201.) — Recapitulation.

Age of more

In treating of the lacustrine deposits of Central France,
in the seventeenth chapter, I omitted, in order to
avoid confusion, all details respecting the associated
volcanic rocks, to which I now recall the reader's at-
tention. (See the Map, p. 145.)

It was stated that, in the arenaceous and pebbly
group of the lacustrine basins of Auvergne, Cantal,
and Velay, no volcanic pebbles had ever been detected,
although massive piles of igneous rocks are now found
in the immediate vicinity. As this observation has
been confirmed by minute research, we are warranted
in inferring that the volcanic eruptions had not com-
menced when the older subdivisions of the freshwater
groups originated.

In Cantal and Velay no decisive proofs have yet
been brought to light that any of the igneous out-
bursts happened during the deposition of the fresh*

VOLCANIC ROCKS OF AUVERGNE.

185

Wat er strata ; but there can be no doubt that in
•^uvergne some volcanic explosions took place before
Jj 16 drainage of the lakes, and at a time when the
■"°cene species of animals and plants still flourished.

as relating to the

1 shall

first advert to these proofs

story of the period under consideration, and shall then
" °ceed to show that there are in the same country
01c anic rocks of much newer date, some of which
Ppear to be referable to the Miocene era.
Volcanic rocks associated with lacustrine in Au-

*er\

'ffne, — The first locality to which I shall call the

fader's attention is Pont du Chateau, near Clermont,

, kieh spot, as well as others in Auvergne, mentioned

lri this chapter, I examined, with Mr. Murchison, in

8 28. The section is seen in a precipice on the right

atl k of the river Allier. Here beds of volcanic tuff

ter nate with a freshwater limestone, which is in some

a ces pure, but in others spotted with fragments of

c &nic matter, as if it were deposited while showers

Sa nd and scoriae were projected from a neighbouring

Vol

*U.* This limestone contains the Helix Ramondi
** other shells of Eocene species. It is immaterial
the present argument whether the volcanic sand was
. °^ered down from above, or drifted to the spot by a
er ; for the latter opinion must presuppose the
^ntry to have been covered with volcanic ejections
rj fig the Eocene period.

Mother example occurs in the Puy de Marmont,
ar ^eyres, where a freshwater marl alternates with
canic tuff containing Eocene shells. The tuff or
ec cia in this locality is precisely such as is known to
u 't from volcanic ashes falling into water, and sub-

* See Scrope's Central France, p. 21c

i i

>'f

186

EOCENE PERIOD.

[Book

IV.

MM.

siding together with ejected fragments of marl and
other stratified rocks. These tuffs and marls are highly
inclined, and traversed by a thick vein of basalt, which,
as it rises in the hill, divides into two branches.

, Gergovia The hilL of Gergovia, near Clermont,

affords a third example,
and Jobert that there is no alternation here of lava
and freshwater strata, in the manner supposed by some
other observers*; but the position and contents of
some of the tuffs prove them to have been derived
from volcanic eruptions which occurred during the
deposition of the Eocene formations.

The bottom of the hill consists of slightly inclined
beds of white and greenish marls, more than three
hundred feet in thickness, intersected by a dike of
basalt, which may be studied in the ravine above the

Merdo

The dike here cuts through the

marly strata at a considerable angle, producing, "*
general, great alteration and confusion in them fot

Fig.

154.

L- l I I INI' 1 / 1 j ', ' J

.g*

capP in '

3 White a-,,
yellow ^

Hill of Gergovia.

* See Scrope's Central France, p. 7.

° h - Xix.

VOLCANIC ROCKS OF AUVERGNE.

187

s °me distance from the point of contact. Above the

hl te and green marls, a series of beds of limestone

( * marl, containing freshwater shells, are seen to

e *nate with volcanic tuff. In the lowest part of

ls division, beds of pure marl alternate with compact

fissil

Ital

6 tuff, resembling some of the subaqueous tuffs of

y and Sicily called peperinos. Occasionally frag-

% e *Us of scoriae are visible in this rock. Still higher

Se en another group of some thickness, consisting

, c 'usively of tuff, upon which lie other marly strata

te ^mixed with volcanic matter.

■There are many points in Auvergne where igneous

° c ks have been forced by subsequent injection through

a ys and marly limestones, in such a manner that the

w hol e has become blended in one confused and brec-

Clat ed mass, between which and the basalt there is

betimes no very distinct line of demarcation. In

e cavities of such mixed rocks we often find calce-

0t) y> and crystals of mesotype, stilbite, and arragonite.

L ° formations of this class may belong some of the

ec cias immediately adjoining the dike in the hill of

er govia; but it cannot be contended that the vol-

at *ic sand, and scoriae interstratified with the marls

**d limestones in the upper part of that hill were in-

r °duced, like the dike, subsequently, by intrusion from

e W. They must have been thrown down like sedi-

. en t from water, and can only have resulted from

b^eous action, which was going on contemporaneously

!t h the deposition of the lacustrine strata.

The reader will bear in mind that this conclusion

§ r ^es well with the proofs, adverted to in the seven-

ee *tth chapter, of the abundance of silex, travertin,

nc * gypsum precipitated when the upper lacustrine

•

- .

188

EOCENE PERIOD.

[Book

clV.

strata were formed ; for these rocks are such as the wa-
ters of mineral and thermal springs might generate.

The igneous products above mentioned, as asso-
ciated with the lacustrine strata, form the lowest

members of tl

great

series of volcanic rocks
Auvergne, Cantal, and Velay, which repose for the most

part on

(see Map

Ihere was evidently a long succession of eruptions-
beginning with those of the Eocene period, and ending'
so far as can yet be inferred from the evidence de-
rived from fossil remains, with those of the Miocene
epoch. The oldest part of the two principal volcanic

perhaps belong to the Eocene period, — the ne* er

Miocen

as Etna commenced its operations during the Ne^er
Pliocene era, and has continued them down to the
Recent epoch, and still retains its energy undiminished-

There are some parts of the Mont Mezen, in Velay>
which are perhaps of the same antiquity as the oldest
parts of Mont Dor.

Besides these ancient rocks, of which the lavas are
in a great measure trachytic, there are many minor
cones in Central France, for the most part of poste-
rior origin, which extend from Auvergne, in a direction
north-west and south-east, through Velay, into the
yivarais, where they are seen in the basin of the

This volcanic line does not pass by the
Plomb du Cantal ; it was formed, as nearly as can be
conjectured in the present imperfect state of our
knowledge, during the Miocene period; but there
may probably be found, among these cones and their
accompanying lavas, rocks of every intermediate age

Ardeche.

Ch.

XIX3

MONT DOR.

189

^een the oldest and newest volcanic formations of
te »tral France.

Mont

d the Plomb du Cantal, and then pass on to the train

newer cones, examining the evidence at present

tamed respecting their relative ages, and the light

% llc h they throw on the successive formation of allu-

Urr *s and on the excavation of valleys.

Dor

Mont

e volcanic masses of Auvergne, rests immediately on

e granitic rocks standing apart from the freshwater

rata.* This volcano rises suddenly to the height of

ev eral thousand feet above the surrounding platform,

^ retains the shape of a flattened and somewhat irre-

Sular cone, all the sides sloping more or less rapidly,
11 W their inclination is gradually lost in the Jiigh

\ a ' l n around. This cone is composed of layers of sco-
^5 pumice-stones, and their fine detritus, with inter-

!° s ^d beds of trachyte and basalt, which descend often

Uninterrupted currents, till they reach and spread

)er fiselves round the base of the mountain.* Con-

£ derates also, composed of angular and rounded
a gftients of igneous rocks, are observed to alternate
lt; h the above ; and the various masses are seen to
P off from the central axis, and to lie parallel to the
°ping flanks of the great cone, in the manner I have
Scribed when treating of Etna.

, ■'■he summit of the mountain terminates in seven or
gat rocky peaks, where no regular crater can now

, e traced, but where we may easily imagine one to
aVe existed, which may have been shattered by earth-

* a kes, and have suffered degradation by aqueous

* See the Map, p. 145.

f Scrope's Central France, p. 98.

;

"■ m

190

EOCENE PERIOD.

[Book

IV.

agents. Originally, perhaps, like the highest crater ot
Etna, it may have formed an insignificant feature m
the great pile, and may frequently have been destroyed

and renovated.

the

Mont

age

of the

have yet been found in the tuffs, except impression 5
of the leaves of trees of species not determined-
Some of the lowest parts of the mountain are formed
of white pumiceous tuffs, in which animal remains ma)'
perhaps be one day found. In the mean time, we ma,V
conclude that Mont Dor had no existence when the
grits and conglomerates of the Limagne, which contain
no volcanic materials, were formed ; but some of the
earliest eruptions were, perhaps, contemporary wit' 1
those described in the commencement of this chapter*
To the latest of these eruptions, on the other hand, 1
refer those trachytic breccias of Mont Perkier which
were shown in the sixteenth chapter (p. 134.)

Mioce

Velay.

have not yet established that any of the most ancient
volcanos of Velay were in action during the Eocene
period, although it is very probable that some of then 1
may have been contemporaneous with the oldest of the
Auvergne lavas. There are beds of gravel in Vety>
as in Auvergne, covered by lava at different height
above the channels of the existing rivers. In the high-
est and most ancient of these alluviums the pebble 5
are exclusively of granitic rocks ; but in the ne*er>
which are found at lower levels, they contain an inter-
mixture of volcanic substances. I have already sho^n*
in the sixteenth chapter, that, in the volcanic ejection 5
and alluviums covered by the lavas of Velay, the bone 5

^ XIX.]

PLOMB DU CANTAL.

191

ot animals of Miocene species have been found, in
v hich respect the phenomena accord perfectly with
th °se of Auvergne.

k Womb du Cantal. — In regard to the age of the
§ n eous rocks of the Cantal we are still less informed,
Jj^ at present can merely affirm, that they overlie the
° c ene lacustrine strata of that country. (See Map,
** H5.) They form a great dome-shaped mass, which
as evidently been accumulated, like the cone of Etna,
Uring a long series of eruptions. It is composed of
^chytic, phonolitic, and basaltic lavas, tuffs, and con-
secrates, or breccias, forming a mountain several thou-
sand feet in height. Dikes also of phonolite, trachyte,
an d basalt are numerous, especially in the neighbour-
ed of the large cavity, probably once a crater, around
^ich the loftiest summits of the Cantal are ranged
Ocularly, few of them, except the Plomb du Cantal,
1Sln g far above the border or ridge of this supposed
la ter. A pyramidal hill, called the Puy Griou, occu .
P Ies the middle of the cavity.* It is evident that the
°'cano of the Cantal broke out precisely on the site
the lacustrine deposit before described (Chapter
ll «), which had accumulated in a depression of a
ac t composed of micaceous schist. In the breccias,
er * to the very summit of the mountain, we find
^3 e cted masses of the freshwater beds, and sometimes
ra gments of flint, containing Eocene shells* Valleys
a diate in all directions from the central heights of the
°untain, increasing in size as they recede from those
ei ghts. Those of the Cer and Jourdanne, which are
0r e than twenty miles in length, are of great depth,
n u lay open the geological structure of the mountain.

/ j

■.

* Mem. de la Soc. G£ol. de France, torn. i. p. 175.

192

EOCENE PERIOD.

Book IV-

No alternation of lavas with undisturbed Eocene strata
has been observed, nor any tuffs containing freshwate
shells, although some of these tuffs include fossil re-
mains of terrestrial plants said to imply several distinc
restorations of the vegetation of the mountain m li
intervals between great periods of eruption. On t
northern side of the Plomb du Cantal, at La Vissier<J>
near Murat, is a spot, pointed out on the Map (p- l^v

where freshwater limestone and marl are seen covei
by a thickness of about eight hundred feet of volcafl 1
rock. Shifts are here seen in the strata of limestone

and marl.*

Although it appears that the lavas of the Cantal at

than the freshwater formation of ^ a

more recent

country, it does not follow that they may not belo n »
to the Eocene period. The lake may possibly ha^

been drained by the earthquakes which preceded °
accompanied the first eruptions, but the Eocene an 1 '
mals and plants may have continued to exist for a 1°^
series of ages, while the cone went on increasing in
dimensions.

»/

I shall next consi^ r

those minor volcanos, before alluded to, which stretc
in a long range from Auvergne to the Vivarais, aD
which appear for the most part to be of newer orig 1
than the mountains above described. These volcano
were faithfully described, so early as the year \W^
by M. de Montlosier.f They have been thrown up in
a great number of isolated points, and much resell 1
those scattered over the Phlegrsean fields and the flan**
of Etna. They have given rise chiefly to currents o

* See Lyell and Murchison, Ann. des Sci. Nat., Oct. 1829-
| Theorie des Vole, d' Auvergne. — Clermont, An X.

C ^. XIX.]

VOLCANOS OF AUVERGNE.

193

Baltic lava, whereas those of Mont Dor and the
c antal are in great part trachytic. There are perhaps
a bout 300 of these minor cones in Central France ; but
a Part of them only occur in Auvergne, where some

e ^ are found at the bottom of valleys excavated
r ough the more ancient lavas of Mont Dor, as the

u y de Tartaret, for example, whence issues a current
°* lava which, flowing into the bed of the river Couze,
gave rise to the lake of Chambon. Here the more

^cient columnar basalts of Auvergne are seen form-
lI1 g the upper portion of the precipices which bound
tll e valley.

But the greater part of the minor cones of Auvergne
are placed upon the granitic platform, where they
f ° r m an irregular ridge, about eighteen miles in length
^*d two in breadth. They are usually truncated at
*he summit, where the crater is often preserved entire,

he lava having issued from the base of the hill.

re quently the crater is broken down on one side,
^We the lava has flowed out. The hills are composed
°* loose scoriae, blocks of lava, lapilli, and puzzuolana,
^ lt; h fragments of trachyte and granite.

The lavas may be often traced from the crater to
*he nearest valley, where they usurp the channel of
the river, which has often excavated a deep ravine
trough the basalt. We have thus an opportunity of
Cor *trasting the enormous degradation which the solid
***d massive rock has suffered by aqueous erosion, and
Jhe integrity of the cone of sand and ashes which has,

But

^the

mean time, remained uninjured on the neigh-

boring platform, where it was placed beyond the reach
* the power of running water.
Puyde Come. — The Puy de Come and its lava cur-
re *it, near Clermont, may be mentioned as one of the

Vol. iv.

.-T

■ f

194

EOCENE PERIOD.

[Book

clV-

numerous illustrations of the phenomenon here alluded
to.* This conical hill rises from the granitic platform?
at an angle of about 40°, to the height of more than
900 feet. Its summit presents two distinct craters,
one of them with a vertical depth of 250 feet. A
stream of lava takes its rise at the western base of the
hill, instead of issuing from either crater, and descends
the granitic slope towards the present site of the
town of Pont Gibaud. Thence it pours in a broad
sheet down a steep declivity into the valley of the
Sioule,, filling the ancient river-channel for the distance
of more than a mile. The Sioule, thus dispossessed °*
its bed, has worked out a fresh one between the la va
and the granite of its western bank ; and the excava*
tion has disclosed, in one spot, a wall of column**
basalt about 50 feet high.f f

The excavation of the ravine is still in progress?
every winter some columns of basalt being undermined
and carried down the channel of the river, and in the

d pebbl

course of a few miles rolled to sand an

Meanwhile the cone of Come remains sfau .. J7

loose materials being protected by a dense vegetation?
and the hill standing on a ridge not commanded by
any higher ground whence floods of rain-water may
descend.

Puy Rouge. — At another point, farther down the
course of the Sioule, we find a second illustration of
the same phenomenon in the Puy Rouge, a conical hill
to the north of the village of Pranal. The cone is
composed entirely of red and black scoriae, tuff, and
volcanic bombs. On its western side there is a worn-

'i *

■

* Montlosier, Theorie des Vole. d'Auvergne, ch. ii.
f Scrope's Central France, p.' 60., and plate.

<*. XIX.]

ALLUVIUMS OF DIFFERENT AGES.

195

^n crater, whence a powerful stream of lava has

^sued, and flowed into the valley of the Sioule. The
ly er has since excavated a ravine through the lava
an d subjacent gneiss, to the depth of 400 feet.

On the upper part of the precipice forming the left

1( *e of this ravine, we see a great mass of black and

e d scoriaceous lava ; below this a thin bed of gravel,

Vl( iently an ancient river-bed, now at an elevation of

*ty feet above the channel of the Sioule. The gravel

§ a in rests upon gneiss, which has been eroded to the

e pth of 50 feet.* It is quite evident in this case,

l ^at, while the basalt was gradually undermined and

Car ried away by the force of running water, the cone

Whence the lava issued escaped destruction, because it

st °od upon a platform of gneiss several hundred feet

*"ove the level of the valley in which the force of

inning water was exerted.

At is needless to multiply examples, or the Vivarais

0l *ld supply many others equally striking. Among

a &y I may instance the cone of Jaujac, and its lava

Ur ^ent, which is a counterpart of that near Pranal

■■

st mentioned.^

avas and alluviums of different ages. — We have

av e flowed at the bottom of the Val del Bove, at the

eer * that on the flanks of Etna, since the commence-
et *t of the present century, several currents of lava

° ot of precipices formed of more ancient lavas and

u ** s * So we find in Auvergne that some streams of

e *ted matter have flowed in valleys, the sides of

lll ch consist partly of older lavas. These are often

^ See Lyell and Murchison on the

di *i. New Phil. Journ., July, 1829.

t Serope's Central France, plate 14.

K 2

Excavation of Valleys,

■

196

EOCENE PERIOD

[Book IV.

seen capping the hills in broad sheets, resting some-
times on granite, sometimes on freshwater strata.

Many of the earlier lavas of Auvergne flowed out
upon the platform of granite before all the existing
valleys had been excavated; others again spread them-
selves in broad sheets over the horizontal lacustrine
deposit, when these had been covered with gravel
probably soon after the drainage of the lakes. Great
vicissitudes in the physical geography of the country
must have taken place since the flowing of these an*

m *

cient lavas ; and it is evident that the changes were
gradual and successive, caused probably by the united
agency of running water and subterranean movements*
We frequently observe one mass of lava capping a
hill, and a second at a lower elevation, forming a ter*

race on the side of a valley ; or sometimes occupying
the bed of a river.

It is a most interesting fact, that in these cases beds
of gravel almost invariably underlie the successive
currents of lava, as in Catalonia before described
(pp. 95. 98.). Occasionally, when the highest plat-
form of lava is seven hundred or eight hundred feet
above the lowest, we cannot fail to be struck with the

Fig. 1 55.

Lava
Gravel/

jBcd ofJR

Lava,

Lavas of Auvergne resting on alluviums of different ages.

» i

Ch -XlX.] ALLUVIUMS OF DIFFERENT AGES.

197

Wonderful alterations effected in the drainage of the
country since the first current flowed ; for the most
e Wated alluviums must originally have been accumu-
lat ed on the lowest levels of the then existing surface.
^ s some geologists have referred almost all the super-
nal gravels to one era, and have supposed them to
" e the result of one sudden catastrophe, the pheno-
mena of Auvergne here alluded to are very important.
*V flows of volcanic matter have, in fact, preserved
P 0r tions of the surface in the state in which they ex-
ited at successive periods ; so that it is impossible to
Coi *found together the alluviums of different ages,
^he reader will see at once by reference to the wood.
c Ut (pig. 155.V that a considerable interval of time
^st have occurred between the formation of the up-
permost bed of gravel and that next below it ; during
^hich interval the uppermost lava was poured out, and
a v alley excavated, at the bottom of which the second
, e d of gravel accumulated. In like manner the pour-
ln g out of a second current of lava and a further
Opening of the valley, took place between the date
°f the second gravel and that of the modern alluvium
^hich now fills the channel of the river.*

When rivers are dispossessed of their channels by
av a, they usually flow between the mass of lava and
° n e side of the original valley. They there eat out a
^ssage, partly through the volcanic and partly through
^e older formation; but as the soft tertiary marls

* For localities in Central France where lavas or sheets of
asalt repose on alluviums at different elevations above the present
v all e y Sj an( j f or the i n f erences deducible from such facts, consult

the works of MM. Le Grand d'Aussi, Montlosier, Ramond,
Scr ope, Bertrand de Doue, Croizet, Jobert, and Bouillet.

K 3

i !

198

EOCENE PERIOD.

[Book

IV.

■)

in Auvergne give way more readily than the basalt
it is usually at the expense of the marls that the en-
larging and deepening of the new valley is effected ;
so that all the remaining lava is then left on one side
in the manner represented in the above woodcut.

It might have been

expected, from the analogy of modern changes in vol"
canic countries, that we should find in Auvergne some
signs of ancient fissures caused by earthquakes. Ac-
cordingly M. Fournet has observed in the course of
excavations made for mining in the valley of the Sioule?
near Clermont, some curious and decisive proofs of the
former existence of open rents which must have coW
municated with the surface, and have been filled froi* 1
above with alluvium, after the commencement and
before the end of the period of volcanic eruptions. #
appears that a metaliferous vein traversing gneiss (**>
other words, a mass or dike of matter, partly metalH c
and partly not, filling an old fissure in the gneiss) had
been dislocated by later convulsions, so that a ne^
rent was formed in it which reached the surface*
Sand and gravel like that of a river-bed were then
washed in, together with pieces of wood, which are
now found fossil with the gravel, in a good state of pre-
servation. The rounded pebbles are partly of granite
rocks, partly of basaltic and augitic lava, showing that
the last filling up of the fissure occurred after some
lavas had flowed over the adjacent country. But W°
of the most modern lava streams near Pont Gibau^
have passed over the top of the dike, and they must
evidently have been poured out after it was filled with
alluvium.*

* See Fournet, Traite de Geog., D'Aubuisson, torn. iii. p. 544-

•

Ch - XIX.]

AGE OF AUVERGNE VOLCANOS.

199

The only organic

rer *iains found as yet in the ancient alluviums appear

Miocene

^fte discovered in the gravel underlying the newest
avas, — those which either occupy the channels of the
listing rivers, or are very slightly elevated above
^em. I think it not improbable that even these may

Miocene date, although the conjecture will ap-
extremely rash to some who are aware that the

c °ttes and craters whence the lavas issue are often as
^sh in their aspect as the majority of the cones of

^e forest zone of Etna.

The brim of the crater of the Puy de Pariou, near
Vermont, is so sharp, and has been so little blunted
h time, that it scarcely affords room to stand upon.
This and other cones in an equally remarkable state of
integrity have stood, I conceive, uninjured, not in spite
of their loose porous nature, as might at first be na-
sally supposed, but in consequence of it. No rills
Ca n collect where all the rain is instantly absorbed by
^e sand and scoriae, as was shown to be the case on

£t

(

and

s Pout breaking directly upon the Puy de Pariou could
Ca **ry away a portion of the hill, so long as it is not
re nt or engulphed by earthquakes.

Attempt to divide volcanos into ante-diluvian
Post-diluvian. — The opinions above expressed are en-
tirely at variance with the doctrines of those writers
^ho have endeavoured to arrange all the volcanic cones
°f Europe under two divisions, those of ante-diluvian
^d those of post-diluvian origin. To the ante-diluvian
C W they attribute such hills of sand and scoriae as
e *hibit on their surface evident signs of aqueous de-
lation; to the post-diluvian, such as betray no marks

K 4}

L-

200

EOCENE PERIOD.

[Book

IV.

of having been exposed to such aqueous action. Ac-
cording to this classification, almost all the minor cones
of Central France must be called post-diluvian; al-
though, if we receive this term in its ordinary accept-
ation, as denoting posteriority of date to the Noachian
deluge, we are forced to suppose that all the volcanic
eruptions occurred within a period of little more than
twenty centuries, or between the era of the flood
which happened about four thousand years ago, an
the earliest historical records handed down to us re-
specting the former state of Central France. D r#
Daubeny has justly observed, that had any of these
French volcanos been in a state of activity in the ag e
of Julius Caesar, that general, who encamped upon the
plains of Auvergne, and laid siege to its principal city
(Gergovia, near Clermont), could hardly have failed
to notice them. Had there been even any record of
their existence in the time of Pliny or Sidonius Ap°*'

linaris, the one would scarcely have omitted to make
mention of it in his Natural History, nor the other to
introduce some allusion to it among the descriptions
of this his native province. This poet's residence was
on the borders of the Lake Aidat, which owed its very
existence to the damming up of a river by one of the
most modern lava-currents.*

The ruins of several Roman bridges, and of the
Roman baths at Royat, confirm the conclusion that no
sensible alteration has taken place in the physical geo-
graphy of the district, not even in the chasms exca-
vated through the newest lavas since ages historically
remote. We have no data at present for presuming
that any one of the Auvergne cones has been pro-

Daubeny on Volcanos, p. 14.

wer

BlatelS.

IS .Foreland.

imsaate

teal

S. Foreland

hlkesttmA

Deia&t:
ess

FEYENSEYB.

O^OOITAJL

c tke South East t

BeactarH?

Exhibiting t/ieDemidatwn

he WE A

1 Tertiary
Strata

Chalk and
Firestone

Gault

ower Green
Sand

\WeaId(2*i%>

UL ngs id

Ch - XIX.]

DILUVIAL THEORIES.

201

<Wd within the last four or five thousand years ; and

*e same may be said of those of Velay ; and, until

** e bones of men or articles of human workmanship

re found buried under some of their lavas, instead of

ne remains of extinct animals, which alone have

kith

erto been met with, we are justified in regarding
as probable that the latest of the volcanic eruptions
a y have occurred during the Miocene period.

Supposed effects of the Flood.

They who have used the terms ante-diluvian and
P° s t-diluvian, in the manner above adverted to, pro-
Cee d on the assumption that there are clear and une-
^ivocal marks of the passage of a general flood over
al * parts of the surface of the globe. It had long been
a Question among the learned, even before the com-
mencement of geological researches, whether the de-
u §e of the Scriptures was universal in reference to the
hole surface of the globe, or only so with respect to
^at portion of it which was then inhabited by man.
} the latter interpretation be admissible, it will appear
^ 0t ^ other parts of this work that there are two
as ses of phenomena in the configuration of the earth's
u *face, which might enable us to account for such an
Ve nt. First, extensive lakes elevated above the level
°* the ocean; secondly, large tracts of dry land de-
ceased below that level. When there is an immense
a ^e, having its surface, like Lake Superior, raised six
Undred feet above the level of the sea, the water may
e suddenly let loose by the rending or sinking down
the barrier during earthquakes, and thereby a region
e *tensive as the vallev of the

Miss

K 5

;

\l i

202

EOCENE PERIOD.

[Book

IV.

by a population of several millions, might be deluged
On the other hand, if there be any country placed
beneath the mean level of the ocean, as some h& ve
supposed to be the case with part of Asiaf, *^ e
depressed region must be entirely laid under water?
if the tract which separates it from the ocean be 6 s '
sured or depressed to a certain depth. Humboldt
inferred, from the observations of Parrot, that a g reat
cavity existed in Western Asia, eighteen thousand
square leagues in area, and occupied by a consideraW
population. J The lowest parts, surrounding the C&>"
pian Sea, were said to be about 350 feet below ^ e
level of the Euxine, — here, therefore, the diluvia

waters might overflow the summits of hills rising

350

feet above the level of the plain ; and if depression
still more profound existed in any former time lJ1
Asia, the tops of still loftier mountains may ha^ e
been covered by a flood.

* Vol. I. p. 133. f Vol, III. p. 126.

| Fragmens Asiatiques, Paris, 1831.

§ Since the above passage was first written, Professor Pari"
of Dorpat, has published his " Reise zum Ararat," in which &
doubts, nay, appears wholly to have disproved, the fact so l 0lly
believed on bis authority, of a difference of level between ^
Black Sea and the Caspian. The opinion was originally adop te
on the authority of barometrical measurements, made by him a11
M. Engelhard t in 1811. M. Parrot, however, on revisiting ^ e
country in 1829 and 1830, was led to suspect the correctness °
his former observations on several grounds, one of which only
shall now quote. Russian engineers had ascertained, by accur* te

measurements, that the Don, at the place called Katschalii^
where it is only sixty wersts distant from the Wolga, is 130 P arlS
feet higher than the latter river, and that the Don flows with m u ° a
greater rapidity to the Black Sea than the Wolga does to tft
Caspian ; consequently, if there be a difference of level of the t*°
seas, it must be considerably less than 1 30 feet. Parrot according 1 ;'

■

Ch - XIX.]

DILUVIAL THEORIES.

203

But the great majority of the older commentators
av e held the deluge, according to the brief account of

th
of

e event given by Moses, to have consisted of a rise

Waters over the whole earth, by which the summits

the loftiest mountains on the globe were submerged,

* any have indulged in speculations concerning the

s fruments employed to bring about the grand cata-

ysfti ; and there has been a great division of opinion

to the effects which it might be expected to have

Produced on the surface of the earth. According to
116 school, of which De Luc formerly, and in our
^tt times Dr. Buckland, have been zealous supporters,
^ e passage of the flood worked a considerable alter-

atl °n in the external configuration of our continents.
y Dr. Buckland the deluge has been represented as

Vl ng determined to ascertain the true state of the case, made a
r *es of levellings from the mouth of the Wolga to Zarytzin,
wersts up its course, and from the mouth of the Don to the
e distance. As the result of these observations, he made the
0t *th of the Don to be between three and four feet lower than
at of the Wolga ! Baron Humboldt, who with other geographers
^ given full credit to the former statement of Parrot, refused to
^it the validity of these new results, unless the professor was
e pared to show that his former observations were less worthy of

0lv &dence. In reply to this, Parrot, in an Appendix, admits
at their barometrical instruments used in 1811 were imperfect,
at errors had crept into his calculations, that he was suffering

ror ** ill health, &c. &c.

Notwithstanding this recantation, M. Erman, of Berlin, in his

Reise um die erde," &c. 1828-29-30., infers from independent

^rvations that the Caspian is lower than the Black Sea by 42- 8

Ses j or about 280 feet; and Meyer and Lenz, in a paper read

toi

° the Academy of Sciences in St. Petersburgh in 1835, mention
at Mr. Goebel, by his barometrical measurements in 1833, found

* dim

erence of 50 feet.

K 6

204

EOCENE PERIOD.

[Book 1^'

a violent and transient rush of waters which tore up
the soil to a great depth, excavated valleys, gave rise
to immense beds of shingle, carried fragments of rock
and gravel from one point to another ; and, during its
advance and retreat, strewed the valleys, and even the
tops of many hills, with alluvium.*

But I agree with Dr. Fleming, that in the narrative
of Moses there are no terms employed that indicate
the impetuous rushing of the waters, either as they
rose or when they retired, upon the restraining of tne

the contrary, the olive-branch, brought back by the
dove, seems as clear an indication to us that the veg e *
tation was not destroyed, as it was then to Noah that
the dry land was about to reappear.

I have been led with great reluctance into this
digression, in the hope of relieving the minds of some
readers from groundless apprehension respecting the
bearing of many of the views advocated in this work
They have been in the habit of regarding the diluvia
theory above controverted as alone capable of affording
an explanation of geological phenomena in accordance
with Scripture, and they may have felt disapprobation
at an attempt to prove, in a former chapter, that the
minor volcanos on the flanks of Etna may, some of
them, be more than 10,000 years old.J How, they
would immediately ask, could they have escaped the
denuding force of a diluvial rush of waters ? The same

* Buckland, Reliquia? Diluvianae. These opinions, however?
have been candidly renounced in a note in his Bridgewater Treatise-

f Rev. Dr. Fleming, on the Geological Deluge, Edin. P hil#
Journ., vol. xiv. p. 205.; and remarks by myself in the Quarter!?
Review, Oct. 1827, No. lxxii. p. 481.

| Vol. III. p. 430.

Ch. xix.]

DILUVIAL THEORIES.

205

Ejection may have presented itself when I quoted,
^ J th respect, the opinion of a distinguished botanist,

at some living specimens of the Baobab tree of
Africa, or the Taxodium of Mexico, may be 5000 years

**• The reader may also have been astonished at
J*e high antiquity assigned to the greater part of the
European alluviums, and the many different ages to

hl ch I have referred them f , as he may have been

u ght to consider the whole as the result of one recent

^d simultaneous inundation.

Professor Sedgwick is inclined to adopt the hypo-

e sis of M. Elie de Beaumont, that the sudden ele-

Va tion of mountain-chains "has been followed again
atl d again by mighty waves desolating whole regions
°*the earth %\" a phenomenon which he thinks has
^ken away all anterior incredibility from the fact of

a r ecent deluge." _

"ut I cannot admit that there are sufficient geolo-

£ lc &l data for inferring such instantaneous upheavings
* submerged land as might be capable of causing a
°°d over a whole continent at once. I may also ob-

" erv e, that the reasoning above alluded to seems to

P r °ceed entirely on the assumption that the flood of
<>ah was brought about by natural causes, just as
°*tte writers have contended that a volcanic eruption
as the instrument employed to destroy Sodom and

°*tiorrah. If we believe the flood to have been a

et *iporary suspension of the ordinary laws of the

*ttural world, requiring a miraculous intervention of

lv ine power, then it is evident that the credibility of

* See Vol. III. p. 428.

t Vol. IV. p. 45. f Vol. III. p. 431.

§ Sedgwick, Anniv. Address to the Geol. Soc, Feb. 18th,

206

EOCENE PERIOD,

[Book

IV.

such an event cannot be enhanced by any series ot in-
undations, however analogous, of which the geology*
may imagine that he has discovered the proofs.

For my own part, I have always considered the
flood, when its universality in the strictest sense of the
term is insisted upon, as a preternatural event far be-
yond the reach of philosophical inquiry, whether as to
the causes employed to produce it, or the effects most
likely to result from it- At the same time, it is clear
that they who are desirous of pointing out the coin-
cidence of geological phenomena with the occurrence
of such a general catastrophe, must neglect no one ot

Mosa

least of all so remarkable a fact as that the olive re-
mained standing while the waters were abating.

Recapitulation. — I shall now briefly recapitulate
some of the principal conclusions to which we have
been led by an examination of the volcanic districts of
Central France.

1st. Some of the volcanic eruptions of Auvergne
took place during the Eocene period; others at an
era long subequent, probably during the Miocene
period.

2dly. There are no proofs as yet discovered that
the most recent of the volcanos of Auvergne and Velay
are subsequent to the Miocene period, ihe integrity
of many cones and craters not opposing any sound
objection to the opinion that they may be of very
great antiquity.

3dly. There are alluviums in Auvergne of very
different ages, some of them belonging to the Miocene
period. Many of these have been covered by lava-
currents which have been poured out in succession
while the excavation of valleys was in progress.

Ch * XIX.]

RECAPITULATION.

207

There

e lay, and the Vivarais, which have never been sub-
J ec ted to the action of a violent rush of waters capable
Modifying considerably the surface of the earth.

Sthl

Mosaic

^ted as universal, and as having exercised a violent

eri uding force, all these cones, several hundred in
nu mber, must be post-diluvian,
othly. But since the beginning of the historical era,
the invasion of Gaul by Julius Caesar, the volcanic

c tion in Auvergne has been dormant; and there is
^°thing to countenance the idea that, between the date
Us Ually assigned to the Mosaic deluge and the earliest
tra ditional and historical records of Central France
( a period of little more than twenty centuries), all or
atl y one of the more entire cones of loose scoriae were
t} *own
Lastly. It is the opinion of some writers, that the

ar th's surface underwent no great modification at the
er * of the Mosa

Potation of the Scriptural narrative does not warrant

? *n expecting to find any geological monuments of

^ e catastrophe ; an opinion which would be consistent

tth the preservation of these volcanic cones, however

*§h their antiquity.

208

CHAPTER XX.

eocene formations — continued.

Basin of the Cotentin, or Valognes — Rennes — Basin of the
Netherlands — Aix, in Provence — Fossil insects — Vicente
Tertiary strata of England — Basins of London and Ha^P*
shire — Different groups — Plastic clay and sand — London
clay (p„ 214.) — Bagshot sand — Freshwater strata of the l sle
of Wight — Palasotherium and other fossils of Binstead— Eng'
lish Eocene strata conformable to chalk — Outliers on tbe
elevated parts of the chalk (p. 218.).

In addition to the Eocene formations treated of in the
last three chapters, there are others in the north oi
Europe, the geographical position of which is de-
lineated on the annexed map.*

Basin of the

The strata i»

the environs of Valognes, in the department of 1*

Manche

noyers has given an elaborate description. It is occa-
sionally covered with a compact freshwater limestone
alternating with freshwater marls. In these Eocene
strata more than 300 species of fossil shells have been
discovered, almost all identical with species of * ne

* This map is copied from one given by M. Desnoyers, Mei»*
de la Soc. d'Hisr. Nat. de Paris, 1 825, pi. 9. ; compiled partly
from that author's observations, and partly from Mr. Webster' 3
map, Geol. Trans., First Series, vol. ii. plate 10.

Ch - XX. l

EOCENE FORMATIONS.

209

n s basin. Superimposed upon the Eocene strata of
m is a newer marine deposit, extending over a

thi s basi

*Ui>

°F THE PRINCIPAL TERTIARY BASINS OF THE EOCENE

PERIOD.

*tr

Primary rocks and

W%%\ Eocene formations.

a older than the carbonife-
° Us series.

f r • The space left blank is occupied by secondary formations
the old red sandstone to the chalk inclusive.

t , lte d area, the fossils of which agree with those of

. * a luns of the Loire.* Here, therefore, the geolo-

of has an opportunity of observing the superposition

■k ^e Miocene deposits upon those of the age of the

ari * basin.

str

e nnes Several small patches, also, of marine

. ata > have been found by M. Desnoyers, in the
p o^bourhood of Rennes, which are characterized by
g ° ei *e fossils, and repose on ancient rocks, as will be
een in the map.

* D

esnoyers, Mem. de la Soc. d'Hist. Nat. de Paris, 1825.

210

EOCENE PERIOD.

[Book

IV.

Basin of Belgium, or the Netherlands.— The greats
part of the tertiary formations of the Low Countries
consist of clay and sand, much resembling those of & e
basin of London, afterwards to be described ; and th*
fossil shells are of the same species.

Aix in Provence — -The tertiary strata of Ai* an
Fuveau, in Provence, are of great thickness and extend
the lower members being remarkable for contain^
coal grit and beds of compact limestone, such as in
England are found only in ancient secondary group 1 "
Yet these strata are for the most part of freshwa^ r
origin, and contain several species of Eocene shell 5 '
together with many which are peculiar to this bas jr1 '
It will require a fuller comparison than has yet b^
made of the fossil remains of Aix and Fuveau, befc re
we can determine with accuracy the relative age °
this formation. Some of the plants seem to agree ^
those of the Paris basin, while many of the inseC ts
have been supposed identical with species now living'

These insects have been almost exclusively procure
from a thin bed of grey calcareous marl, which pas^J
into an argillaceous limestone found in the quarries ° f
gypsum near Aix. The rock in which they are iP
bedded is so thinly laminated, that there are sometir^ 5
more than seventy layers in the thickness of an i^'
The insects are for the most part in an extraordin

ary

~ — — ^+ — ■■■ ■■* ^^ *** %* J-^ V* Mm ft* M.JLJL till V/^Tk. C J- Ct/ \J -** *-**•*-

state of preservation, and an impression of their &f
is seen both on the upper and under lamina?, as in

the

Monte

M. Marcel

enumerates sixty-two genera, belonging chiefly to tb e
orders Diptera, Hemiptera, and Coleoptera. On * e '

* M. Marcel de Serres, Geog;. des Ter. Tertiaires du Midi

la France,

Ch « xx.

ENGLISH EOCENE FORMATIONS.

211

jewing a collection brought from Aix, Mr. Curtis
^serves that they are all of European forms, and most
them referable to existing genera * With the

singi

rail

e exception of an Hydrobius, none of the species

a quatic. The antennae, tarsi, and trophi are gene-
7 very obscure, or distorted ; yet in a few the
a ^s are visible, and the sculpture, and even some
§ r ee of local colouring, are preserved. The nerves
the wings, in almost all the Dipt era, are perfectly
hnct, and even the pubescence on the head of one
them. Several of the beetles have the wings ex-
uded beyond the elytra, as if they had made an effort
es cape by flying, or had fallen into the water while
0tl the wing.f
dentine. — On the Southern flank of the Alps to

the
tai

°thp

fcorth of Vicenza, in Italy, a limestone occurs con-
nin g shells of Eocene species, and in the basaltic

(

)

(Pi

Basins of London and Hampshire.

e reader will see in the small map above given

*§• 156. p. 209.), the position of the two districts

a % called the basins of London and Hampshire,

^hich the Eocene formations of England are con-

e( h These tracts are bounded by rising grounds

. ^posed of chalk, except where the sea intervenes.

^ a t the chalk passes beneath the tertiary strata, we

11 ttot only infer from geological data, but can prove

^urchison and Lyell. Ed. New Phil. Journ., Oct. 1829.
' Curtis, ibid., where figures of some of the insects are given.
* S *e H st of species collected by M. Boue, and named by M.
esh ayes, Bull, de la Soc. Geol. de France, tomeiii. p. 91. '•

212

EOCENE PERIOD.

[Book

IV.

ells

by numerous artificial sections at points where w
have been sunk, or borings made through the over-
lying beds. The Eocene deposits are chiefly marine
and have generally been divided into three groups :
1st, the Plastic clay and sand, which is the lo^es 1
group; 2dly, the London clay; and, 3dly, the Bagsh ot
sand. Of all these the mineral composition is very
simple, for they consist almost entirely of clay, san<*»
and shingle, the great mass of clay being in the middle
and the upper and lower members of the series bei*$
more arenaceous.

Plastic clay and sand. — The lowest formation, vM<^
sometimes attains a thickness of from four hundred W
five hundred feet, consists principally of an indent
number of beds of sand, shingle, clay, and loam, irr e '
gularly alternating, some of the clay being used '"
potteries, in reference to which the name of Plast^
clay has been given to the whole formation. The be** 8
of shingle are composed of perfectly rolled chalk flin ts '
with here and there small pebbles of quartz. Heap*
of these materials appear sometimes to have remair> e<1
for a long time covered by a tranquil sea. Dr. Bu^'
land mentions that he observed a large pebble in p art
of this formation at Bromley, to which five full-gro^
oyster-shells were affixed, in such a manner as to sho^
that they had commenced their first growth upon i£
and remained attached through life.*

In some of the associated clays and sand, perfe<*
marine shells are met with, which are of the sa& e
species as those of the London clay. The line oi
separation, indeed, between this superincumbent blu e
clay and the Plastic clay and sand is quite arbitrary*
as any geologist may be convinced who examines the

* Geol. Trans., First Series, vol. iv. p. 300.

Ch - XX.

]

ENGLISH EOCENE FORMATIONS.

213

e ebrated section in Alum Bay, in the Isle of

er e a distinct alternation of the two groups is ob-
p e rVa ^ le ' eac h marked with their most characteristic
^ culiarities.* In the midst of the sands of the lower

Co* 68 - a - maSS ° f clay occurs two hundred feet thick,
of ntainin § septaria, and replete with the usual fossils

the neighbourhood of London.f

he arenaceous beds are chiefly laid open on the
foil neS °f the basins of London and Hampshire, in
^ °Wing which we discover at many places great

s of perfectly rounded flints. Of this description,

tn e southern borders of the basin of London, are

,7 h il]s of Comb
^ich

Hurst and the Addington hills,
form a ridge stretching from Blackheath to

, °ydon. Here they have much the appearance of
t n( * s of sand and shingle formed near the shores of a
o . lar y sea; but whether they were really of littoral
8 1X * cannot be determined, for want of a sufficient
. ^ber of sections, which might enable us to compare

t r tertiar y strata at the edges with those in the cen-
a ' Parts of each basin.

^e have ample opportunities in the basin of Paris

Hamming steep cliffs of hard rock, which bound

i y of the valleys, and innumerable excavations

e been made for building-stone, limestone, and

v , P Su m ; but when we attempt to obtain a connected

^ T ° f atly considerable part of the tertiary series

to o basin of London > we are almost entirely limited
Q single line of coast-section ; for in the interior

■

Serj "° e Mr ' Webster ' s Memoir, Geol. Trans., vol. ii., First
les > and his Letters in Sir H. Englefield's Isle of Wight.

See Mr, Webster's Sections, plate 11. Geol. Trans., vol. ii.,
st Series.

;

214

EOCENE PERIOD.

[Book

IV.

the regular beds are much concealed by an allu v j al
covering of flint gravel spread alike over the summit
and gentle slopes of the hills, and over the bottoms oi
the valleys.

Organic remains are extremely scarce in the Pla stlC
clay ; but when any shells occur, they are of Eocen e
species. Vegetable impressions and fossil wood &*

sometimes met with, and even beds of lignite;
none of the species of plants have, I believe, as y
been ascertained.

London clay — This formation consists of a \fa& $
or blackish clay, sometimes passing into a calcareo^

marl, rarely into a solid rock. Its thickness is vetf

great, sometimes exceeding five hundred feet,
contains many layers of ovate or flattish masses °
argillaceous limestone, which, in their interior, & e .
generally traversed in various directions by crack

partially or wholly filled by calcareous spar. TheS e
masses, called septaria, are sometimes contintf^
through a thickness of two hundred feet.f

A great number of the marine shells of this cW
have been identified with those of the Paris basin ; &
it is quite evident that the strata of these two basi° s
belong to the same epoch.

No remains of terrestrial mammalia have as yet \>e&

found in this clay ; but the occurrence of bones a n< *

, skeletons of crocodiles and turtles prove, as Mr. Conf

beare justly remarks, the existence of neighbouring

, dry land. The shores, at least, of some islands wefj

\ accessible, whither these creatures may have resorted

to lay their eggs. In like manner, we may infer the coV

* Con. and Phil. Outlines of Geol., p. 33
f Outlines of Geol., p. 27.

Ch - XX.1

LONDON AND HAMPSHIRE BASINS.

215

^suity of land from the immense number of ligneous
c ed " Ve ssels of plants, some of them resembling the
^ Oc oa-nut, and other spices of tropical regions, which

J*e been found fossil in great profusion in the Isle of
PPey. Such is the abundance of these fruits, that

, e yhave been supposed to belong to several hundred

ls ^ct species of plants.

She
th

^ffshot sand.

The third and uppermost group,

«"'y termed the Bagshot sand, rests conformably

%tT ^ G ' tj0ndon cla y' and consists of siliceous sand
Sa ndstone, devoid of organic remains, with some

f deposits of marl associated. From these marls a
. Marine shells have been obtained which are in an
P er fect state, but appear to belong to Eocene species
Or ^mon to the Paris basin.*

re shwater strata of the Hampshw

o ^ rt Wn part of the Isle of Wight, and part of the
^P°site coast of Hampshire, freshwater strata occur
lllpr on the London clay. They are composed

In the

ci %;

of calcareous and argillaceous marls, inter-

ed with some thick beds of siliceous sand, and

„._ — j „_„.

^arls are often green, and bear a considerable
v> ^blance to the green marls of Auvergne and the

,> basin. ~

Hig

The shells and gyrogonites also agree
cally with some of those most common in the

^ nc h deposits. Mr. Webster, wno nrst aescrii
j * r eshwater formation of Hampshire, divided
v e . ari u Pper and lower series, separated by inter-
Ce n 8 ^eds of marine origin. There are undoubtedly
an , tain intercalated strata, both in the Isle of Wight
c oast of Hampshire, marked by a slight inter-

Warburton, Geol. Trans., vol. i., Second Series.

216

EOCENE PERIOD.

[Book

IV.

mixture of marine and freshwater shells, sufficient to
imply a temporary return of the sea, before and afte r
which the waters of the lake, or rather, perhaps, soto e
large river, prevailed.* The united thickness of * be
freshwater and intercalated upper marine beds, &'
posed in a vertical precipice in Headen Hill, in tbe

series appearing about half way up in the cliff.

Eocene mammift

Very perfect

re-

mains of tortoises and the teeth of crocodiles h& e

•1]

been procured from the freshwater strata ; but a &
more interesting discovery has recently been m aC * e '
The bones of mammalia, corresponding to those °
the celebrated gypsum of Paris, have been disinter^

Wight

Intl*

ancient quarries near this town a limestone, beloV$'
ing to the lower freshwater formation, is worked # r
building. Solid beds alternate with marls, wherein a
tooth of an Anoplotherium, and two teeth of & e
genus Palaeotherium, were found. These remains w^ re
accompanied not only by several other fragments °

a 1 1 n TT* 11 /" * * **. • ill r%flt*

(chiefly

injured state), but also by th
Ruminantia, apparently cloi

Moschus.f Mr. T. Allan o & « _

years before found the tooth of an Anoplotherium *
the same spot.

fit

These newer strata of the Isle of Wight be&
certain degree of resemblance to some of the % xe ^

Fir^

* See Memoirs of Mr. Webster, Geol. Trans., vol.ii.*
Series; vol. i. parti., Second Series; and Englefield's Is le

Professor Sedgwick, Ann. of Phil., 1822; and I>>

Wight.

Geol. Trans., vol. ii., Second Series.
f Pratt, Trans, of Geol. Soc, vol. iii. partiii. p. 451

relh

r act

ft our

X X.] EOCENE STRATA CONFORMABLE TO CHALK. 217

Jjaris and limestones in the Paris basin ; yet, as a whole,
ormations can be more dissimilar in mineral cha-
er than the Eocene deposits of England and Paris.

s lv l ~ ° Wn island the tertiar y strata are more exclu-
Ser - marbe ; and h rai S ht be said th at the Parisian
!es differs chiefly from that of London in the very

^ints in which it agrees with the formations of Au-

o/l 116 ' CantaI ' and Velav - The tertiary formations

^ ijngland are, in fact, almost exclusively of mecha-

s origin, and their composition bespeaks the ab-

I h ° e °^ those m i nera ' an d thermal waters to which

av e attributed the origin of the compact and sili-

°Us limestones, the gypsum, and beds of pure flint,

^ttion to the Paris basin and Central France.

the
th

u7l glisli tertiary strata conformable

! British Eocene strata are nearly conformable to

chalk on which they rest, being horizontal where

^ strata of the chalk are horizontal, and vertical

e >* they are vertical. On the other hand, there

^ evident signs that the surface of the chalk had,

^any places, been furrowed by the action of the

8^ and Currents ' before the Pla stic clay and its

cll ^ een of deep indentations on the surface of the
*K into which sand, together with rolled and

K ar
^ 8e appearances may be referred to the action of

^oc^ Whei l the Chalk began t0 emer ge during the
Coi) Cene . Period, and they by no means warrant the

s .^ c usion that the chalk had undergone any con-

s were superimposed. In the quarries near Ro-
ster and Gravesend, for instance, fine examples

' -O *»* "'«■" iVAiiGU. cum

f pieces of chalk-flint, have been swept.* But

q eraki i- n ° —

ciDie change of position before the tertiary strata

re superimposed.

v ol.

Con. and Phil., Outlines of.GeoI., p. 62

IV,

218

EOCENE PERIOD.

■

[Book

IV.

In this respect there is a marked difference between
the reciprocal relations of our secondary and tertiary
rocks, and those which exist between the same groups
throughout the greater part of the" Continent, espe-
cially in the neighbourhood of mountain-chains. Near
the base, for example, of the Alps, Apennines, an
Pyrenees, we find the newer formations reposing u°'
conformably upon the truncated edges of the older
beds; and it is clear that, in many cases, the older
strata had been subjected to a complicated series &■
movements before the more modern set was formed-
The newer beds rise only to a certain height on the
flanks of the mountains which usually tower abo^e
them, and are recognized at once by the geologist a s
having been already converted into land when the
tertiary deposits were still forming in the sea. The
ancient borders, also, of that sea can often be define**
with certainty, and the outline of some of its bays an (1
sea-cliffs traced.

In England, although undoubtedly the neater pe r '
tion of the tertiary strata is confined to certain spaced
we find outlying patches here and there at great dis-
tances beyond the general limits, and at great height
upon the chalk which separates the basins of London
and Hampshire .* I have seen masses of clay extend-
ing in this manner to near the edge of the western
escarpment of the chalk of Wiltshire, and Mr. Mantel
has pointed out the same to me in the South Do^nS-
Near the escarpment at Lewes, for example, there » s
a fissure in the chalk filled with sand, and with a fer-
ruginous breccia, such as usually marks the lo* er
members of the Plastic clay formation. From the
occurrence of these tertiary outliers Dr. Buckland in-

* Dr. Buckland, Geol. Trans., Second Series, vol. ii. p. ^ 5 '

xx.a

TERTIARY OUTLIERS ON CHALK.

219

s, and the plains of Andover and Basingstoke in

rred, " that the basins of London and Hants were
gmally united together in one continuous deposit

Cl *OSS t.h<3 nrmr ;«#.^«*r«^: ~1 II. „I? 0_1!_1 Til-?.. :_

Wii t

ant s ; and that the greater integrity in which the

T tiary strata are preserved within the basins has re-

te d from the protection which their comparatively

^ position has afforded them from the ravages of

Qllu vial denudation."*

a gree so far with this conclusion as to believe that

e basins of London and Hampshire were not sepa-
e d until part of the tertiary strata were deposited ;
1 1 do not think it probable that the tertiary beds
extended continuously over those spaces where

e v er

e °utliers above mentioned occur, nor that the com-
bative thinness of those deposits in the higher chalk
^ Entries should be attributed chiefly to the greater
§ r ee of denudation which they have there suffered.

<ie

^r, Buckland, Geol. Trans., Second Series, vol. ii. p. 126.

■ I

h 2

220

CHAPTER XXI.

■

ORIGIN OF THE ENGLISH EOCENE FORMATIONS ANP

DENUDATION OF THE WEALD.

Manner in which the English tertiary strata may have" origin* 48

r ^^

Denudation of secondary strata during their deposition
Valley of the "Weald — Secondary rocks of the Weald divisi^ e
into five groups — North and South Downs — Section acr° sS
the valley of the Weald — Anticlinal axis — Chalk escarpm eIltS
once sea-cliffs (p. 226. ) — Rise and denudation of the stra ta
gradual — Parallel ridges and valleys formed by harder an a
softer beds — No ruins of the chalk on the central district « f
the Weald (p. 234.) — Double system of valleys, the longi t0 '
dinal and the transverse (p. 237. ).

Preliminary

In explanation of the phenorne Jl3

described in the last chapter, I shall now endeavour t°
lay before the reader a view of the series of event 8
which may have produced the leading geological an<*
geographical features of the south-east of England- *
conceive that the chalk, together with many subjacent
rocks, may have remained undisturbed and in horizon^ 1
stratification until after the commencement, of & e
Eocene period. When at length the chalk was up*
heaved and exposed to the action of the waves and cur-
rents, it was rent and shattered, so that the subjacent
secondary strata were soon after exposed to denudation
The waste of all these rocks, composed chiefly of sand-
stone and clay, supplied materials for the tertiary

Ch - XXI,

DENUDATION OF THE WEALD.

221

s ands and clays ; while the chalk was the source of
inty shingle, and of the calcareous matter which we
n d intermixed with the Eocene clays. The tracts
° w separating the basins of London and Hampshire
er e those first elevated, and which contributed by
eir gradual decay to the production of the newer
r ata. These last were accumulated in deep submarine
°'Ws, formed probably by the subsidence of certain
P ai% ts of the chalk, which sank while the adjoining
acts were rising.

denudation of the Valley of the Weald. — In order to

^derstand this theory, it will be necessary that the

* e ader should be acquainted with the phenomena of

^ttudation exhibited by the chalk and some of the

°^er secondary rocks in parts of England, most nearly

c °ntiguous to the basins of London and Hampshire.

1 will be sufficient to consider one of the denuded

ls tricts, as the appearances observable in others are

str ictly analogous ; I shall, therefore, direct attention

what may be called the Valley of the Weald> or

l he region intervening between the North and South

^owns.

l\L

The district alluded to is delineated in the

Coloured map, given in Plate XV., which has been
c hiefly taken from Mr. Greenough's Map of England ;
atl d it will be there seen that the southern portion of

** e basin of London, and the north-eastern limits of that
°* Hampshire, are separated by a tract of secondary

° c ks, between forty and fifty miles in breadth, com-
posing within it the whole of Sussex, and parts of the
c °Unties of Kent, Surrey, and Hampshire.

There can be no doubt that the tertiary deposits of
tlle Hampshire basin formerly extended much farther
alo &g our southern coast towards Beachy Head, for

l 3

I !

222

EOCENE PERIOD.

[Book

clV.

patches are still found near Newhaven, and at other

points, as will be seen by the map. These are no^

wasting away, and will in time disappear, as the sea &

constantly encroaching and un dermining the subjacent
chalk.

The secondary rocks, depicted on the map, may
divided into five groups :

Chalk and upper green-sand.

This group

the uppermost of the series ; it includes the
white chalk with and without flints, and an hi'

ferior deposit, called, provincially, " Firestone
and by English geologists, the " Upper green-
sand." It sometimes consists of loose siliceous
sand, containing grains of silicate of iron, b ut
often of firm beds of sandstone and chert.

2. Blue clay or calcareous marl, called, provincially'

Gault.

3. Lower green-sand, a very complex group, con-

sisting of grey, yellowish, and greenish sands I
ferruginous sand and sandstone ; clay, chert>
and siliceous limestone.

4. Weald clay, composed for the most part of clay

without intermixture of calcareous matter, h ut
sometimes including thin beds of sand and
shelly limestone.

5. Hastings sands, composed chiefly of sand, sand-
stone, clay, and calcareous grit, passing in t0

limestone.*

The first three formations above enumerated are of
marine origin ; the last two, Nos. 4. and 5., contain

* For an account of these strata in the south-east of Engl*"*
see Mantell's Geology of Sussex, and Dr. Fitton's Geology ° f

Hastings, where the memoirs of all the writers on this part

England are referred to.

Ch - XXI.]

DENUDATION OF THE WEALD.

22°

almost exclusively the remains of freshwater and am-
phibious animals. But it is not my intention to enlarge,
at present, upon the organic remains of these form-
ations, as the rocks are merely adverted to in order
l hat I may describe the changes of position which they
«ave undergone, and the denudation to which they
We been exposed since the commencement of the
Eocene period, — mutations which, if the theory about
to be explained be well founded, belong strictly to the

^story of tertiary phenomena.

By a glance at the map, the reader may trace at
0r *ce the superficial area occupied by each of the five
t0r mations above mentioned.

On the west will be

s een a large expanse of chalk, from which two branches
ar e sent off ; one through the hills of Surrey and Kent
to Dover, forming the ridge called the North Downs ;
a &d the other through Sussex to the sea at Beachy
**ead, constituting the South Downs. The space com-
posed between the North and South Downs, or, " the
Galley of the Weald," consists of the formations Nos.
2 > 3, 4, 5. of the above table. It will be observed that
the chalk terminates abruptly, and with a well-defined
^e towards the country occupied by those older
str ata. Within that line is a narrow band, coloured
hhae, formed by the gault ; and within this again, is
the Lower green-sand, next the Weald clay; and then,
"> the centre of the district, a ridge formed by the
"astings sands.

yfthe Valley of the Weald

It has been as-

certained by careful investigation, that if a line be
<Wn from any part of the North to the "South Downs,
^hich shall pass through the central group (No. 5.),
t«e beds will be found arranged in the order described

mthe

(Fig. 157.)

L 4

•;

•Ki

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■

*C ^

*K»

fc. J

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03
co

0»

<3
co

Ctt

tf>

to O

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CX)

03 .CU

0) CO

t*H

03 &P

5 O

e O

< O

CD
• CO

§ 8

g o>

o
P

o g

JS.

.05

« U

s go

CO G>

c3 £

«0

3 * Z.

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G 'o3

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&

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QJ p4

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• A

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fc w

t* 03

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^ 3-

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Ch - XXI.]

"DENUDATION OF THE WEALD.

225

The reader is referred at present to the dark lines
of the section, as the fainter lines represent portions
°* rock supposed to have been carried away by denu-
dation.

At each end of the diagram the tertiary strata, a,
ar e exhibited reposing on the chalk. In the centre

(No. 5.)

lc hnal axis, on each side of which the other form-

tl ons are arranged with an opposite dip. It has been

Pessary, however, in order to give a clear view of

y e different formations, to exaggerate the propor-

tl °nal height of each in comparison to its horizontal

ext ent; and a true scale is therefore subjoined in

Mother diagram (Fig. 158.), in order to correct the

err oneous impression which' might otherwise be made

° n the reader's mind. In this section the distance

between the North and South Downs is represented

exceed forty miles ; for the Valley of the Weald is

er e intersected in its longest diameter, in the direc-

l0r * of a line between Lewes and Maidstone.

*ft attempting to account for the manner in which
^ e five secondary groups above mentioned may- have

e en brought into their present position, the following
ypothesis has been very generally adopted :— Suppose
** e five formations to lie in horizontal stratification
1 the bottom of the sea ; then let a movement from
elow press them upwards into the form of a flattened
0tl *e, and let the crown of this dome be afterwards
Cu t off, so that the incision should penetrate to the
0Mr est of the five groups. The different beds would
^ e n be exposed on the surface, in the manner ex-
ited in the map, PL XV. *

See illustrations of this theory by Dr. Fitton, Geol. Sketch

of JJ

astings.

L 5

■1

226

EOCENE PERIOD.

[[Book

IV.

It will appear, from former parts of this work, that
the amount of elevation here supposed to have taken
place is not greater than we can prove to have oc-
curred in other regions within geological periods of n°
great duration. On the other hand, the quantity ^
denudation or removal by water of vast masses which
are assumed to have once reached continuously f rom
the North to the South Downs is so enormous, that the
reader may at first be startled by the boldness of the
hypothesis. But he will find the difficulty to vanish
when once sufficient time is allowed for the gradual
and successive rise of the strata, during which the
waves and currents of the ocean might slowly accofl 1 '
plish an operation, which no sudden diluvial rush °*
waters could possibly have effected.

Escarpments of the chalk once sea-cliffs. — In order t°
make the reader acquainted with the physical struc-
ture of the Valley of the Weald, I shall suppose hi#
first to travel southwards from the London basin. O n
leaving the tertiary strata he will first ascend a gently
inclined plane, composed of the upper flinty portion oi
the chalk, and then find himself on the summit of *
declivity consisting, for the most part, of different
members of the chalk formation ; below which the
upper green-sand, and sometimes also the gault, crop
out.* This steep declivity is called by geologists " &e
escarpment of the chalk," which overhangs a valle}'
excavated chiefly out of the argillaceous or marly beA-
termed Gault (No. 2.). The escarpment is continuous
along the southern termination of the North Down s >
and may be traced from the sea at Folkstone, west-

* This term, borrowed from our miners, is used to express the
coming up to the surface of one stratum from beneath another.

•K.

Is*

«*»

C<1

■St

■to

J><>

•Ki

H3
O

•73

c«

227

228

EOCENE PERIOD.

[Book

IV.

ward to Guildford and the neigbourhood of Peters-
field, and from thence to the termination of the South

■Downs at Beachy
Head. In this pre-

<a
Si

■8 .

Co s

cipice

steep

slope the strata % te
cut off abruptly?
and it is evident
that they must
originally have &*
tended farther- I 11

the accompany^
wood-cut, (Fig*
159.), part of the
escarpment of the
South Downs lS

>•$

faithfully

repre-

sented, where th e
denudation at the
base of the decli-
vity has been som e '
what more extefl'
sive than usual, &
consequence of the
upper and lo^ er
green-sand being
formed of very incoherent materials, the upper, indeed
being extremely thin and almost wanting.

The geologist cannot fail to recognize in this vie^
the exact likeness of a sea-cliiF; and if he turns and
looks in an opposite direction, or eastward, towards
Beachy Head (see Fig. 160.), he will see the same l& e
of height prolonged. Even those who are not accus*
tomed to speculate on the former changes which the

Ch - XXI.

]

DENUDATION OF WEALD VALLEY.

229

*ace has undergone may fancy the broad and level

plain

to resemble the flat sands which were laid dry by

^ceding tide, and the different projecting masses

c halk to be the headlands of a coast which separated
th * diffi

th
of

erent bays from each other.

•outer terrace of firestone. — I have said that the

Pper green-sand (" firestone," or "malm-rock" as it

0r netimes called) is almost absent in the tract here
al Wed to.

°*tto

It is, in fact, seen at Beachy Head to thin

, t0 an inconsiderable stratum of loose green-sand ;
farther to the westward it is of great thickness,

contains hard beds of blue chert and limestone.

ere ? accordingly, we find that it produces a corre-
^flding influence on the scenery of the country ; for

r Uns out like a step beyond the foot of the chalk-

~ s > and constitutes a lower terrace, varying in breadth
, *** a quarter of a mile to three miles, and following

e 8 muosities of the chalk escarpment. *

Fig. 161.

^ Chalk with flints.

b. Chalk without flints.

*at
in

* Upp er green-sand, or firestone. d. Gault.

' is impossible to desire a more satisfactory proof
* the escarpment is due to the excavating power of

er during the rise of the strata ; for I have shown
*£ m y account of the coast of Sicily, in what manner
e encroachments of the sea tend to efface that suc-

s Mr. Murchison, Geol. Sketch of Sussex, &c, Geol. Trans
c °nd Series, vol. ii. p. 98.

■

230

EOCENE PERIOD.

• [Book

IV.

the

cession of terraces which must otherwise result frofl 1
the . successive rises of a coast preyed upon by
waves.* During the interval between two elevato 1 */
movements, the lower terrace will usually be de-
stroyed, wherever it is composed of incoherent ma te "
rials ; whereas the sea will not have time entirely t0
sweep away another part of the same terrace, or lo* ef
platform, which happens to be composed of rocks oi *
harder texture, and capable of offering a firmer re***'
ance to the erosive action of water.

Valleys where softer strata, ridges where harder c r °t
It is evident that the gault No. 2. (see the M^P/
could not have opposed any effectual resistance to t fl
denuding force of the waves ; its outcrop, therefa re '
is marked by a valley, the breadth of which, is <$&
increased by the loose incoherent nature of the upp er '
most beds of the lower green-sand, which lie next t0
it, and which have often been removed with eq ua
facility.

This formation (the lower green-sand) has b eeI *

sometimes entirely smoothed off like the gault ; but

in those districts where chert, limestone, and oth e

out

solid materials enter largely into its composition
forms a range of hills parallel to the chalk, which so& e '
times rival the escarpment of the chalk itself in heig bt '
or even surpass it, as in Leith Hill. This ridge oft e *
presents a steep escarpment towards the Weald cW
which crops out from under it. (See the strong ^ e$
in Fig. 157. p. 224.)

The clay last mentioned forms, for the most part

broad valley, separating the lower green-sand from ^ e
Hastings sands, or Forest ridge; but where subordin*^

* See Vol. III. p. 440. and wood-cut Fig, 107

* *

Ch >XXl.

beds
f.

]

DENUDATION OF WEALD VALLEY.

231

or sandstone of a firmer texture occur, the uni-
*&ity of the plain is broken by waving; irregularities

and hillocks.* '

H* 1 * the

central

region,

or Forest ridge, the strata

e been considerably disturbed, and are • greatly

ctured and shifted. One fault is known where the

lc al shift of a bed of calcareous grit is no less than

sixt

y fatl

oms.f It must not be supposed that the
th ° ^ ax ^ s ? which is described as running through

the

Weald

dually represented in geological sections. There
]t 5 °n the contrary, a series of anticlinal and syn-
fc a * t lines, which form ridges and troughs running
ar V parallel to each other.

to
°f th

*ch of the picturesque character of the scenery
x s district arises from the depth of the narrow

and

f e ys and ridges to which the sharp bends
ctures of the strata have given rise ; but it is also
Part to be attributed to the excavating power ex-

I e d by water, especially on the interstratified argil-

us beds.

la ce

tK r ° m ^ le a ^ ove description it will appear that, in
j. tr act intervening between the North and South

the

pri

^ n s, there are a series of parallel valleys and ridges ;
% v alleys appearing evidently to have been formed

t / nci Pally by the removal of softer materials, while
^ ri( %es are due to the resistance offered by firmer
s to the destroying action of water.

Let us

n consider how far these phenomena agree with the

tin

Martin, Geol. of Western Sussex.
gs ' P. 31.

Fitton, Geol. of Has-

t P.

itton, Ibid. p. 55.

or explanation of these terms ; see Glossary, Vol. I.

" ;|

232

EOCENE PERIOD.

[Book

IV.

•

changes which we should naturally expect to oc&fl
during the rise of the secondary strata. Suppose the
line of the most violent movements to have coincide
with what is now the central ridge of the Weald valley 5
in that case the first land which emerged must h& e
been situated where the Forest ridge is now placed
Here a number of reefs may have existed, and island
of chalk, which may have been gradually devoured W
the ocean in the same manner as Heligoland and oth er

I
1

. » k

Ch.

XXI.]

DENUDATION OF WEALD VALLEY.

233

°pean islands have disappeared in modern times,
s elated in the second book.*

Ppose the ridge or dome first elevated to have

Su
een

so rent and shattered on its summit as to give

on
th

of
otb

easy access to the waves, until at length the

(Fig. 162.)

e removed. Two strips of land might then remain

each side of a channel,, in the same manner as

°Pposite coasts of France and England, composed

ehalk, present ranges of white cliffs facing each

A powerful current might then rush, like that

now ebbs and flows through the Straits of Dover,

er.

^ich

might scoop out a channel in the gault. We must

^ak

*n mind that the intermittent action of earth

s Ur

Ke s would accompany this denuding process, fis-
* ln g rocks, throwing down cliffs, and bringing up,
*** time to time, new stratified masses, and thus
k at ly accelerating the rate of waste. If the lower
v of chalk on one side of the channel should be
e r than on the other, it would cause an under ter-
se ^ - aS re P resented in the diagram (Fig. 162.), re-
Wing that presented by the upper green-sand in

Sa i S °^ ^ ussex anc * Hampshire. When at length the
of t Was entirely swept away from the central parts
^ th e channel, the lower green-sand (3. Fig. 163.)

W* 1 ^ e laid bare ' and P ortions °f lt would become
q during the continuance of the upheaving earth-

o ke »- Meanwhile the chalk cliffs would recede far-

] a r ° m one another, whereby four parallel strips of

5 °r perhaps rows of islands, would be caused,
o y a continuance of these operations the edges of

ar gillaceous strata, No. 2. (Fig. 163.), would be

• Vol. II. p. 7.

234

EOCENE PERIOD.

[Book

IV.

exposed to farther erosion by the waves ; and a P ortI °!|
of the clay, No. 4., would be also removed, and as
gradually rose, would be swept off from part of ^
subjacent group, No. 5. This last would then & lt *
turn be laid bare, and afterwards become land by sub '
sequent elevation.

Why no ruins of chalk on central district

theory of the successive emergence and denudation

the

groups, 1, 2, 3, 4, 5., we may account for an *

^ vial phenomenon w» l
*£ seems inexplicable
any

cfi

I V

►<l

» *■!

other

hypothe^
^ The summits ~ c

•ed

■

chalk downs are cove 1
every where with **
gravel, which is °*
entirely wanting on
surface of the clay

t S the foot of the

c/3

3 <£

a,
a,

g escarpment,

& traces of chalk flint h*

ever been found in

tr*

C3 r-»

P4 O

w T3

•S

o c
o .-g

S ^ alluvium of the cen
*5 district, or Forest i* 1 ^
It is rare, indeed, to

any wreck of the <# ^
even at the distant

C$ OS

C/2

two or three miles

c foe

L5 O J tE *^ e escar P men ^ s °

.... North and South Do* * S

— . (^ CO ^

a fact attested by

road- surveyors

whoh a

diligently sought for such materials. To this g en
rule, however, an exception occurs near Barco*

ALLUVIUM OF WEALD VALLEY.

235

Ch - XXL

°ut three miles to the north of Lewes, a place which

Vl sited with Mr. Mantell, to whom I am indebted

r ^e accompanying section (Fig. 164.). It will be

n that the valley at the foot of the escarpment ex-

t , s > ln this case, not only over the gault, but over

e " lower green-sand" to the Weald clay. On this

y & thick bed of flints, evidently derived from

^aste of chalk, remains in the position above

bribed.

and

lle n I say that there is no detritus of the chalk
^s flints on the central ridge of the Weald, I may

e that I have sought in vain for a vestige of such
a S^ents; and Mr. Mantell, who has had greater

Pportunities of minute investigation, assures me that

has never been able to detect any. Now, whether

er *ibrace or reject the theory of the former con-

Ul ty of the chalk and other groups over the whole

c e intervening between the North and South Downs,

certainly cannot imagine that any transient and

^Ultiious rush of waters could have swept over this

tK r * tl ^' w hich should not have left some fragments of

.. c halk and its flints in the deep valleys of the Forest

l(J Se
I)
i • Auckland, we should expect to find vast heaps of

p ke n flints drifted frequently into the valleys of the

n, u lt and Weald clay, instead of being generally con-

e( * to the summit of the chalk downs. .

Indeed, if we adopt the diluvial hypothesis of

Un the other hand, it is quite conceivable that the
a gency of oceanic currents may have cleared

Oty

,, j> m the course of ages, the matter which fell into

e s ea from wasting cliffs. But in order that this ex-

t , n Wion should be satisfactory we must suppose that

v e r ise of the land in the south-east of England was

y gradual, and the subterranean movements for the

236

EOCENE PERIOD.

[Book

IV.

most part of moderate intensity. During the last cefl'
tury earthquakes have occasionally thrown down a
once whole lines of sea-cliffs, for several miles con'
tinuously ; but if this had happened repeatedly during
the waste of the ancient escarpments of the chalk n°*'

o-e

companied by the sudden rise and conversion of la'S

1 • I

Weald

with the ruins of those wasted rocks, and the sea c° l]
not possibly have had time to clear the whole a^'
The reader will recollect the account before given °
the manner in which the sea has advanced, within
last century, upon the Norfolk coast at Sherringhatf 1 '

the

Fig. 165.

Beach

.C m

Section of cliffs west of Sherringham.

a. Crag.

b. Ferruginous flint breccia on the surface of the chalk.

c. Chalk with flints.

The beach, at the foot of the cliff, is composed °
bare chalk with flints, as is the bed of the sea « e * r
the shore. No one would suspect, from the appearand* 3
of the beach at low water, that a few years ago b e<JS
of solid chalk, together with sand and loam o( tI,e
superincumbent crag, formed land on the very S P°
where the waves are now rolling ; still less that the se

Vol. I. p. 405,

Cl >. Xxi.

]

TRANSVERSE VALLEYS.

237

e formations extended, within the last fifty years,
a considerable distance from the present shore,
l a space where the sea has now excavated a
clla nnel twenty feet deep.

R s m this recent instance the ocean has cleared

a y part of the chalk, and its capping of crag, so the

iary sea ma y have swept away not only the chalk

founding the valley of the Weald, but the layer of
^en flints on its surface, which was probably a
Uie alluvium of the Eocene period. Hence these
ts might naturally occur on the downs, and be

ln g in the valleys below.
*1 the reader will refer to the preceding diagrams

tti

'S 8 * 162. and 163. p. 232.), and reflect not only on

'" e successive states of the country there delineated,

0n all the intermediate conditions which the dis-

*uust have passed through during the process of

( uual elevation and denudation before supposed, he

, Understand why no wreck of the chalk (No. 1.)

Uld occur at great distances from the chalk escarp-

** ts ; for it is evident that when the ruins of the

ruins would subsequently be carried away when

p P e miost bed (No- 1. Fig. 162.) had been thrown
, n upon the surface of the bed immediately below,

s inferior stratum itself was destroyed. And in pro-

. tlQ n to the number and thickness of the groups,

s Removed in succession, is the probability lessened

° Ur finding any remnants of the highest group

ew ed over the bared surface of the lowest.

* T ansverse valleys. — There is another peculiarity in

e geographical features of the south-east of England,

. lc h must not be overlooked when we are consider-

§ the flpfinn r»f tho r1^nnrlir»<r pqucac. By reference

*e map (Plate XV.), the reader will perceive that

238

EOCENE PERIOD.

[Book

the drainage of the country is not effected by wate r *
courses following the great valleys excavated out o
the argillaceous strata (Nos. 2. and 4.), but by vall^ s
which run in a transverse direction, passing through
the chalk to the basin of the Thames on the one si**
and to the English channel on the other.

In this manner the chain of the North Downs lS
broken by the rivers Wey, Mole, Darent, Med**/'
and Stour; the South Downs by the Arun, Ad ur?

Ouse, and Cuckmere.*

ll
If these transverse hollows could be filled up? a

the rivers, observes Mr. Conybeare, would be fo** ce
to take an easterly course, and to empty themsel^
into the sea by Romney Marsh and Pevensey levels
Mr. Martin has suggested that the great cross fi 1 ^
tures of the chalk, which have become river chanfl el '
have a remarkable correspondence on each side of $
valley of the Weald ; in several instances the gorges &
the North and South Downs appearing to be direcw
opposed to each other. Thus, for example, the de#f
of the Wey, in the North Downs, and of the Arun? in
the South, seem to coincide in direction ; and, in J 1 *
manner, the Ouse corresponds to the Darent, and $

Medway. J

Although these coincidences may, perhaps, be *& v
dental, it is by no means improbable, as hinted by ^
author above mentioned, that the great amount of &'
vation towards the centre of the Weald district g a
rise to transverse fissures. And as the longitudinal **}'

leys were connected with that linear movement

*&&

caused the anticlinal lines running east and west

Conybeare, Outlines of Geol., p. 81. f Ibid., p

.145

$ Geol. of Western Sussex, p. 61.

fc/3

i nT 1

i I rj

>^i

• i>

»'r

iw ; v\

HRfflft

i-™.' f '■

S1H

239

■'/iff"

fffl

mi>

ls;v; .i

U*l

lux

I 1

m ;m

i!v*\\\r

s£3^

i/,i

' lltll

»:

r>/'

■-,

1 n

fa.

,11

t'litu

■/i

'•

i :

» ;

s»:.M*

ft/|

«o

3
«

bX)

-J

24:0

EOCENE PERIOD.

[Book

IV.

■

the cross fissures might have been occasioned by the
intensity of the upheaving force towards the centre oi
the line, whereby the effect of a double axis of elev*'
tion was in some measure produced.

In order to give a clearer idea of the manner &
which the chalk-hills are intersected by these transversa
valleys, I subjoin a sketch (Fig. 166.) of the gorg c
of the river Adur, taken from the summit of the cha^
downs, at a point in the bridle-way leading from & e
towns of Bramber and Steyning to Shoreham. If tlie
reader will refer again to the view given in a forifl er
wood-cut (Fig. 159. p. 227.), he will there see the e^ ci
point where the gorge, of which I am now speaki^
interrupts the chalk escarpment. A projecting h$>
at the point a, hides the town of Steyning, near vM c ^
the valley commences where the Adur passes directly
to the sea at Old Shoreham. The river flows through
a nearly level plain, as do most of the others whi^
intersect the hills of Surrey, Kent, and Sussex; ^
it is evident that these openings, so far at least &
they are due to aqueous erosion, have not been p r °'
duced by the rivers, many of which, like the Ou* e
near Lewes, have filled up arms of the sea, instead ot
deepening the hollows which they traverse.

In regard to the origin of the transverse ravin

es>

Fig. 167.

Supposed section of Transverse Valley.

itb

there can be no doubt that they are connected wi
lines of fracture, and perhaps, in some places, there

Ch.

XXI.]

THE COOMB, NEAR LEWES.

241

^y be an anticlinal dip on both sides of the valley,
as suggested by Mr. Martin.* But this notion requires
c °nfirmation.

Ahe ravine, called the Coomb, near Lewes, affords
dutiful example of the manner in which narrow

hilH'.lttri

P e nings in the chalk may have been connected with
tfts and dislocations in the strata. This coomb is

* Geol. of Western Sussex, p, 64. Plate III. fig. 3
V °L. IV. M

<fi

ii j i

242

EOCENE PERIOD.

[Book

seen on the eastern side of the valley of the Ousft
in the suburbs of the town of Lewes. The steep
declivities on each side are covered with green tun?
as is the bottom, which is perfectly dry. No outward
signs of disturbance are visible ; and the connexi° n
of the hollow with subterranean movements would
not have been suspected by the geologist, had not the
evidence of great convulsions been clearly expo se
in the escarpment of the valley of the Ouse, and in
the numerous chalk pits worked at the termination ° f
the Coomb. By aid of these we discover that the
ravine coincides precisely with a line of fault, on o^ e
side of which the chalk with flints, a, appears at th e
summit of the hill, while it is thrown down to the \>°^
torn on the other. I examined this spot in comp^

with Mr. Mantell, to whom I am indebted for t* 1
accompanying section.

Fig. 169.

Fault in the cliff-hills near Lewes.

a. Chalk with flints.

b. Lower chalk.*

The fracture here alluded to is one of those whi cl1
run east and west, and of which there are many

the Weald district, parallel to the central axis of & e
Forest ridge.

In whatever manner the transverse gorges orig lJ} '
ated, they must evidently have formed ready chann^
of communication between the submarine longitudiP a

•.

* For farther information, see MantelTs Geol. of S. E
England, p. 352.

Ch - XXI.

vail

]

THE COOMB, NEAR LEWES.

^ys and those deep parts of the sea wherein the
r tiary strata may have accumulated. If the strips

and which first rose had been unbroken, and there
ha d b een

th
th

no free passage through the cross fractures,
e currents would not so easily have drifted away

e Materials detached from the wasting cliffs, and it

° u ld have been more difficult to understand how the

e ck of the denuded strata could have been so en-

% swept away from the base of the escarpments.

** the next chapter I shall resume the consideration

'hese 'subjects, especially the proofs of the former

C ° n tinuity of the chalk of the North and South Downs,

to* ^ e Probable connexion of the denudation of the

. ■

V fl

M 2

''■•

■•:,.

v.;

244

CHAPTER XXII

ORIGIN OF THE ENGLISH EOCENE FORMATIONS AND

PE*^'

DATION OF THE WEALD

continued.

■

The alternative of the proposition that the chalk of the North a
South Downs was once continuous, considered — Dr. # u

land on Valleys of Elevation (p. 246.) — If rise and de^

dation of secondary rocks gradual, so also the deposition
tertiary strata (p. 254.) — Composition of the latter such
would result from wreck of denuded secondary rocks

Central parts of the Lo

as high as Weald — Why

Isle of Wight — Eocene alluviums (p. 26S.)
valleys — Recapitulation*

m ana iiampsmre Dasins **—
Curved and vertical strata i»

Formation °

Extent of denudation in the Valley of the Weald.

«v

would be highly rash," observes Mr. Conybeare, sp e

ing of the denudation of the Weald, " to assume
the chalk at any period actually covered the v?

th**

h<^
if

space in which the inferior strata are now expo se
although the truncated form of its escarpment e
dently shows it to have once extended much fart* 1
than at present

I believe that few geologists who have consider
the extent of country supposed to have been denu# > '
and who have explored the hills and valleys of
central or Forest ridge, without being able to disco
the slightest vestige of chalk in the alluvium f> w ,
fail to participate, at first, in the doubts here exp* esS

* Outlines, p. 144

f See' above ; p« 254

Ch.

XXIL]

DENUDATION OF WEALD ;V ALLEY.

245

as to the original continuity of the upper secondary
formations over the anticlinal axis of the Weald. For

lv own part, I never traversed the wide space which
Se parates the North and South Downs, without de-

iring to escape from the conclusions advocated in the
ast chapter ; and yet I have been invariably brought

ac k again to the opinion, that the chalk was origin-

*v continuous, on a more deliberate review of the
w hole phenomena.

It may be useful to consider the only other alter-
native of the hypothesis before explained. If the
Marine groups, Nos. 1, 2, 3., were not originally con-
Fig. 170.

2.
3,

Chalk and Upper

green-sand.
Gault.
•Lower green-sand.

4. Weald clay.

Marine.

Freshwater.

5. Hastings sands

tinu

ous, it is necessary to imagine that they each

err ninated at some point between their present out-
§oings and the secondary strata of the Forest ridge.
*hus we might suppose them to have thinned out one
f*ter the other, as in the above diagram, and never to
^ av e covered the entire area occupied by the fresh-
water strata, Nos. 4. and 5.

It must be granted, that had such been the original
^position of the different groups, they might, as they
§ r adually emerged from the sea, have become denuded
lri the manner explained in the last chapter, so that the
c °Untry might equally have assumed its present con-
figuration. But although I know of no invincible ob-
jection to such an hypothesis, there are certainly no

m 3

\
It

246

EOCENE PERIOD.

[Book

clV.

appearances which favour it. If the strata Nos. 4-
and 5. had been unconformable to the lower green-
sand No. 3.,' then, indeed, we might have imagined
that the older groups had been disturbed by a series of
movements antecedently to the deposition of No. 3.5
and, in that case, some parts of them might be sup-
posed to have emerged or formed shoals in the ancient
sea, interrupting the continuity of the newer marine
deposits. But the group No. 4. is conformable to No. &•
and the only change which has been observed to take
place at the junction is an occasional intermixture o*
the Weald clay with the superior marine sand, such % s
might have been caused by a slight superficial move-
ment in the waters when the sea first overflowed the
freshwater strata.

On the other hand, the green-sand and chalk, % s
they approach the central axis of the Weald, are fl°*
found to contain littoral shells, or any wreck of the
freshwater strata, such as might indicate the exist-
ence of an island with its shores or wasting cliffy
Had any such signs been discovered, we might have
supposed the geography of the region to have once
borne some resemblance to that exhibited in the di&"
gram, Fig. 170.

Dr. BucUand on Valleys of Elevation. — We & xe
indebted to Dr. Buckland for an able memoir in ill uS *
tration of several districts of similar form and structure
to the Weald, which occur at no great distance in the

south of England. His paper is intitled,

On the

Formation of the Valley of Kingsclere and other Val-
leys, by the Elevation of the Strata which inclose
them."*

Geol. Trans, Second Series, vol, h\ p, 119*

^■UH

Ch - XXII.]

VALLEY OF KINGSCLERE.

247

The valley of Kingsclere, a few miles south of New-
bur y, in Berkshire, is about five miles long and two in
breadth. The upper and lower chalk (see Fig. 173.*)
ar *d the upper green-sand dip in opposite directions
* r om an anticlinal axis which passes through the mid-
^ e of the valley along the line a, 6, of the ground-plan

(%.171.>

o
B

•?

<+■<

•

• *-*

«4-i

^ v

-d

t »H

* 1™^

ctt

CL>

-g

bJD

• F— 4

-id

i-.

! I

■ip

In the wood-cut (Fig. 172.) the scale of heights

* Copied by permission from Dr. Buckland's Plate XVI I.,
6e ol. Trans. Second Series, vol. ii.

M 4?

■

■I I

^^^^^■^■a

wmmaaa

248

EOCENE PERIOD.

[Book

IV.

more nearly approaches to that of nature, although the
altitudes, in proportion to the horizontal extent, are
even in this, perhaps, somewhat in excess. On each
side of the valley we find escarpments of chalk, the
strata of which dip in opposite directions, in the north-
ern escarpment to the north, and in the southern to
the south. At the eastern and western extremities
of the valley, the two escarpments become confluent)
precisely in the same manner as do those of the North
and South Downs, at the eastern end of the Weald
district, near Petersfield. And as, a few miles east of
the town last mentioned (see Map, Plate XV.) the fire-
stone, or upper green-sand, is laid open in the sharp
angle between the escarpment of the Alton Hills and
the western termination of the South Downs*; so h 1
the valley of Kingsclere the same formation is seen to
crop out from beneath the chalk.

The reader might imagine, on regarding the section
(Fig. 173.), where, for the sake of elucidating thegeo-

Fig. 1 73.

Section across the Valley of Kingsclere from north to south.

1 . Chal k with flints.

2. Lower chalk without flints.

Upper green-sand, or firestone, containing beds of chert

logical phenomena, the heights are exaggerated i»
proportion to the horizontal extent, that the solution oi

* See Mr. Murchison's Map, Plate XIV., Geol. Trans-
Second Series, vol. ii,

A >

•

Ch - XXII.]

VALLEY OF KINGSCLERE.

249

c °ntinuity of the strata bounding the valley of Kings-
c tae had been simply due to elevation and fracture,
^assisted by aqueous causes; but by reference to the
tr Uer sca i e (Fig- 172.), it will immediately appear that
a considerable mass of chalk must have been removed

v denudation.

If the anticlinal dip had been confined to the valley
of Kingsclere, we might have supposed that the
u pheaving force had acted on a mere point, forcing
upwards the superincumbent strata into a small dome-
s haped eminence, the crown of which had been sub-

quently cut off; but Dr. Buckland traced the line
of opposite dip far beyond the confluence of the chalk
es carpments, and found that it was prolonged in
a more north-west direction far beyond the point a
(Fig. 171.). In following the line thus extended, the
str ata are seen in numerous chalk-pits to have an op-
posite dip on either side of a central axis, from which
w e may clearly infer the linear direction of the move-
ment.

Many of the valleys having a similar conformation
to that of Kingsclere, run east and west, like the

Weald

Several of these

Wiltshire

c ^cumscribed by an escarpment whose component
sti *ata dip outwards from an anticlinal line running
al °ng the central axis of the valley. One of these, dis-
tai *t about seven miles to the north-east of Weymouth,

Nearly elliptical in shape, and in size does not much
e *ceed the Coliseum at Rome. Their drainage is ge-
Orally effected in a manner analogous to the drainage
of the Weald, by an aperture in one of their lateral
es carpments, and not at either extremity of their longer

u 5

il It

•

250

EOCENE PERIOD.

[Book tf.

axis, as would have happened had they been simp 1 )'
excavated by the sweeping force of rapid water.*
« It will be seen," continues Dr. Buckland, " if we fol-

Wilts

that, at no great distance from these small elliptic* 1
valleys of elevation, there occur several longer and
larger valleys, forming deep notches, as it were, in the
lofty edge of the chalk. These are of similar struc-
ture to the, smaller valleys we have been considering*
and consist of green- sand, inclosed by chalk at one ex-
tremity, and flanked by two escarpments of the sainfr
facing each other with an opposite dip ; but they differ
in the circumstance of their other and broader extre-
mity being without any such inclosure, and gradually
widening till it is lost in the expanse of the adjacent

country.

" The cases I now allude to are the Vale of Pe vV "

Warminst

r ; and the Valley of the Naddeft

extending from Shaftesbury to Barford, near Salisbury:

in which last not only the strata of green-sand ar e

brought to the surface, but also the still lower foT&'

ations of Purbeck and Portland beds, and of Kimm e '
ridge clay.

« It might at first sight appear that these valley s
are nothing more than simple valleys of denudation '
but the fact of the strata composing their escarpments
having an opposite and outward dip from the axis of
the valley, and this often at a high angle, as nea r
Fonthill and Barford, in the Vale of the Nadder.
and at Oare, near the base of Martinsell Hill, in the

* Dr. Buckland, Geol. Trans., Second Series, vol. ii. p. l& m

Ch - XXII.]

PROOFS OF DENUDATION.

251

■

Vale of Pewsey, obliges us to refer their inclination
to some antecedent violence, analogous to that to
w hich I have attributed the position of the strata in
^e inclosed valleys near Kingsclere, Ham, and Bur-
gage. Nor is it probable that without some pre-exist-
ln g fracture or opening in the lofty line of the great
c halk escarpment, which is here presented to the
^orth-west, the power of water alone would have
forced open three such deep valleys as those in ques-
tl <>n, without causing them to maintain a more equable
^eadth, instead of narrowing till they end in a point
ir * the body of the chalk.

Now, in the Weald, the strata of the North Downs
ar e inclined to the north at an angle of from 10° to 15°,
0r even 45°, in the narrow ridge of the Hog's Back,
w est of Guildford, in Surrey; while those in the South
^Wns dip to the south at a slight angle. It is super-
fluous to dwell on the analogy which, in this respect,
the two escarpments bear to those which flank the
Alleys above alluded to ; and in regard to the greater
^stance which separates the hills of Surrey from those
of Sussex, the difficulty may be reduced simply to a

Question of time.
If the rise of the land was accomplished by

^definite number of minor convulsions, or by a slow
ar *d insensible upheaving like that now taking place in
Sweden, the power of the ocean would be fully ade-
quate to perform the work of denudation in the lapse
°f many ages. If, on the other hand, we embrace the
Vpothesis of paroxysmal elevation; or, in other w r ords,
f u ppose a submarine tract to have been converted
ln stantaneously into high land, we may seek in vain

! 1 1

Br. Buckland, Geol. Trans. Second Series, vol. ii. p. 12S„

M 6

•

■

252

EOCENE PERIOD.

[Book I"V

for any known cause capable of sweeping away even
those portions of chalk and other rocks which, all are
agreed, must once have formed the prolongation of
the existing escarpments. It is common in such cases
to call in one imaginary cause to support another; and
as the upheaving force operated with sudden violence
so a vast diluvial wave is introduced to carry away?
with almost equal celerity, the mountain mass of strata
assumed to have been stripped off.

Some geologists have endeavoured to account f° r
the structure of the districts described as " valleys °*
elevation," by the aid of Von Buch's theory °*
"elevation craters," in which case they can dispense
both with time and denudation. It would be super-
fluous to repeat what has been already said of the
hypothetical agency here referred to * ; but it mrf
be well to consider whether the upheaving of si»^
dome-shaped masses, such as those described by
Dr. Buckland, implies the development at a con-
siderable depth of volcanic forces acting with great
violence on limited areas, or mere points of the earth's
crust.

far

A theory suggested by Dr. Fitton appears to me
more probable. Suppose a series of horizontal strata?
composed in great part of sand and soft clay, to repo* e
on a foundation of older and more solid rocks present-
ing an uneven surface, varied by hills, valleys, and
ridges, like many parts of the land and bed of the sea*
If a force acting from beneath should then elevate the
whole mass, the protuberances of the subjacent rock*

be forced up against the more compressible

The effect of the pressure

wou

strata which covered them.

Vol, II. p. 152.

MM^^BM

tarn

Ch - XXII.]

ORIGIN OF TERTIARY STRATA.

253

m %ht be the same as that which happens on a small
s cale in a bound book, when a minute inequality or
^ob in the paper of some page is propagated through
a great number of others, imparting its shape to all,
without piercing through them. * The observations
°f Dolomieu on the manner in which the more yielding
te Uiary strata of Calabria were displaced by the granite
^ring the earthquake of 1783, lends some countenance

tothi

In the last chapter I pointed out the phenomena
*hich seem to indicate that the elevation and denud-
ation of land in the south-east of England were

S^dual. t The same ar g uments are in a S reat de g re e
a Pplicable to the basins of Hampshire and the Isle of

Wight ; but Mr. Conybeare has contended that the

Ve rticality of the strata in the Isle of Wight and in
^urbeck compels us to admit that the movement
there was so violent, that the vertical strata, which
have been traced through a district nearly sixty miles
111 length, were brought into their present position by a

Sl ngle convulsion.

Xt may well be asked what ground is there for as-
suring that a single effort of the subterranean force,
r ather than reiterated movements, produced that sharp
flexure of which the vertical strata of the Isle of Wight
a *e supposed to form a part, the remainder of the arc
having been carried away by denudation ? §

It is not improbable that the Cutch earthquake
^ 1819, before alluded to, may have produced an
lr *eipient curve, running in a linear direction through

* Dr. Fitton, Geol. Trans., Second Series, vol. iv. p. 244.

+ See above, Vol. II. p. 215.

| Page 231.

§ See Webster, EnglcSeld's Isle of Wight, Plate XLII. fig. 1

- ■»

254

EOCENE PERIOD.

[Book

IV.

a tract at least sixty miles in length. * The strata
were upraised in the Ullah Bund, and depressed
below the level of the sea in the adjoining tract,
where the fort of Sindree was submerged. (See ?M e
V.) It would be impossible, if the next earthquake
should raise the Bund still higher, and sink to a lower
xlepth the adjoining tract, to discriminate, by any
geological investigations, the different effects of the
two earthquakes, unless a minute survey of the effect
of the first shock had been made and put on record-
In this manner we may suppose the strata to be ben*
again and again, in the course of future ages, until

same

parts of them become perpendicular.

To some it may appear that there is a unity °*
effect in the line of deranged strata in the Isles o*
Wight and Purbeck, as also in the central axis of ^ e
Weald, which is inconsistent with the supposition °*
a great number of separate movements recurring afte r
long intervals of time. But we know that earthquake* 5
are repeated throughout a long series of ages, in the

spots, like volcanic eruptions. The oldest lavas
of Etna were poured out many thousands, perhap 5
myriads of years, before the newest, and yet they
have produced a symmetrical mountain ; and if rive^
of melted matter thus continue to flow in the satn e
direction, and towards the same points, for an * n '
definite lapse of ages, what difficulty is there in con-
ceiving that the subterranean volcanic force, occasioning
the rise or fall of certain parts of the earth's crfl**
may, by reiterated movements, produce the most p ef '

n ... _ -x. P l^ ^

If denudation of secondary rocks gradual, so also de-
position of tertiary. — It follows, then, from the fects

* See Vol. II. p. 194., and Vol. III. p. 253.

'■

;

mmm

Ch - XXII.

ORIGIN OF TERTIARY STRATA.

255

e *atnined in this and the preceding chapter, that
subsequently to the deposition of the chalk a large
re gion composed of secondary strata has been denuded
ail d that the lapse of many ages must have been
Squired for the entire removal of the materials from
*he denuded district.

It is no less evident that the transported matter
11:) u$t have been deposited by degrees somewhere else.
^ r e there any tracts in the south-east of England,
^here we find derivative strata composed of a mixture
°f such mineral ingredients as would result from the
^gradation of the secondary groups Nos. 1, 2, 3, 4,
^ ? The tertiary strata of the London and Hamp-
shire basins answer well to the conditions required by
Su ch an origin, for they consist of alternations of va-
ri ously coloured sands and clays, as do the secondary
str ata from the group No. 5. to No. 2. inclusive. Some

* e *tiary green-sand, which occurs in parts of the
Plastic clay formation in the basins of London and
slants, cannot be distinguished mineralogically from
a large part of that which is found in the secondary
* 0r mations below the chalk.

If it be asked, where do we find the ruins of the

^hite chalk among our Eocene strata? — the answer is,

ars t, that the flint pebbles which are associated in such

Irr miense abundance with the sands of the plastic clay,

are derived evidently from the destruction of chalk,

an d contain the same fossils : secondly, that as to the

°it, white, calcareous matrix, we may suppose it to

av e been easily reduced to fine sediment, and to have

c °*Uributed, when in a state of perfect solution, to

° rr n the shells of Eocene testacea ; or when mixed

Wlt h the waste of the argillaceous groups, Nos. 2. and 4.,

^hich have been peculiarly exposed to denudation, it

256

EOCENE PERIOD.

[Book

IV.

may have entered into the composition of the London
clay, which contains no slight proportion of calcareous
matter. In the crag of Norfolk, undoubtedly, we find
great heaps of broken pieces of white chalk, with
slightly worn and angular flints ; but, in this case, we
may infer that the attrition was not continued for a
long time ; whereas, the large accumulations of p er *
fectly rolled shingle, which are interstratified with our
Eocene formations, prove that they were acted upon
for a protracted period by the waves. We have many
opportunities of witnessing the entire demolition of th e
chalk on our southern coast, as at Seaford, for example
in Sussex, where large masses are, year after year, de-
tached from the cliffs, and soon disappear, leaving no*
thing behind but a great bank of flint shingle.*

It may also be remarked that the white chalk in
the north of England, as in Yorkshire, for example? lS
much harder than the corresponding formation in the
southern counties, where it is now so soft that we mtf
imagine it to have been in the state of mud when
submerged beneath the waters of the sea. An origin^ 1
difference of this kind in the degree of induration m#y
explain the fact, that in certain districts gravel com'
posed of chalk-flint occurs without any pebbles of white
chalk, while in other regions rounded boulders of white
chalk are plentifully intermixed with pebbles of flint*

The similarity, then, of the mineral ingredients o*
the Eocene secondary strata affords alone some p re *
sumption in favour of this newer group having been
derived from the wreck of the older series. But it lS
also natural to expect, that when the formations of th e
Weald were emerging, there would be some contiguous

* Vol. I. p. 424.

Cl1 - XXII.

]

AMOUNT OF DENUDATION.

257

P ar ts of the sea sufficiently deep to receive the drift
Matter.

Fig. 174.

We may suppose, that while the waves and cur-
'^ts were excavating the longitudinal valleys, D
at) d C (Fig. 174.), " the deposits a were thrown down
to the bottom of the contiguous deep water E, the

* e diment being drifted through transverse fissures,
be fore explained.

In this case, the rise of the form-

at ions Nos. 1, 2, 3, 4, 5. may have been going on
c °Qtemporaneously with the excavation of the valleys
C and D, and with the accumulation of the strata a,
^ere must be innumerable points on our own coast
^here the sea is of great depth near to islands and
tiff's now exposed to rapid waste, and in all these the
denuding and reproductive processes must be going on
111 the immediate proximity of each other.
Enalish Eocene

n Wed secondary districts. — Those geologists who have
{^therto regarded the rise and denudation of the lands
111 the south-east of England as events altogether pos-
terior in date to the deposition of the London clay,
**U object to the foregoing reasoning, that not only
Cer tain outlying patches of tertiary strata, but even
tlle central parts of the London and Hampshire basins,
a ttai n very considerable altitudes above the level of
tlle sea. Thus the London clay at Highbeach, in
^ Ss ex, reaches the height of 750 feet ; an elevation
deeding that of large districts of the chalk and other

I
1 i

258

EOCENE PERIOD

[Book

IV.

denuded secondary rocks. But these facts do not,
think, militate against the theory above proposed
since I have endeavoured to show that there must
have been a Jong-continued series of elevatory move-
ments in a region where both the degradation and
reproduction of strata were in progress.

In order to explain this view, I shall assume that,
in the region A (Fig. 175.), the chalk and associate

strata are raised and converted into land ; while in tn e
adjoining district, B, a contiguous part of the sam e
beds remains submerged beneath the sea. During
the elevation in A, the mass c c is gradually remove* 1
by denudation, and its ruins drifted to B, formic
the tertiary deposit d. The force of water has th* 8
exerted an antagonist power ; so that, in spite of ^ e
upheaving movement, the general outline of the soH d
surface, or the relative levels of its various parts, &*
not greatly altered ; for the uppermost part of th e
newer deposit d rises nearly as high as the remaining
summits of the denuded country A. After all these
changes and levelling operations, an elevation to the
amount of eight hundred feet in both the regions A
and B, would cause the secondary rocks of A to ac-
quire much the same height above the level of *h e
sea, as the tertiary beds would attain in B.

The estimate of Mr. Martin is not, perhaps, ex-
aggerated, when he computes the probable thick» eSS

C1) -XX1I.] VERTICAL STRATA OF ISLE OF WIGHT.

259

strata removed from the highest part of the Forest
ge to be about 1900 feet : so that, if we restore to
^ r owborough Hill, in Sussex, the beds of Weald clay,
°^er green-sand, gault, and chalk, which have been
Amoved by denudation, that 'hill, instead of rising
to the height of eight hundred feet, would be more
l W trebled in altitude, and be about 2700 feet high.*

fc ^ould then tower far above the highest outliers
°^ tertiary strata which are scattered over our chalk ;

0r Inkpen Hill, in Berkshire, the greatest elevation
of chalk in England, rises only 1011 feet above the

lev el of the sea.

Some geologists, who have thought it necessary to
Su Ppose all the strata of the London and Hampshire
^sins to have been once continuous, have estimated
tl) e united thickness of the three marine Eocene groups
Wore described, as amounting to 1300 feet, and have
^en bold enough to imagine a mass of this height to
^ av e been once superimposed upon the chalk which
f ° r merly covered the axis of the Weald.f Hence they
Wer e led to infer that Crowborough Hill was once
^° u r thousand feet high, and was then cut down from
° u r thousand to eight hundred feet by diluvial action.
&ut by adopting the view above explained, that the
°cene deposits originated while the chalk and other
Se °ondary rocks were rising from the sea and wasting
* Wa y, we shall find it unnecessary to suppose any re-
moval of formations newer than the chalk, from th

Weald
of the Isle of

A line of ver

lc ^l and inclined strata, running east and west, or

■

Phil. Mag. and Annals, No. 26., New Series, p. 117

f Martin, ibid.

■i? wi !

260

EOCENE PERIOD.

[Book

IV.

Weald

Wight

beck, and through Dorsetshire, and has been observed
by Dr. Fitton to reappear in France, north of Boulogne-
The same strata which are elevated in the Weald
valley are upheaved on this line also ; and in the Is^
of Wight, all the tertiary strata appear to have pa 1 "
taken in the same movement.*

From the horizontality of the freshwater series » n
Alum Bay, as contrasted with the vertical position &
the marine tertiary beds, Mr. Webster was at first led
very naturally to conclude, that the marine had under-
gone great derangement before the deposition of th e
freshwater strata. It appears, however, from the sub'

eq
these

it observations of Professor Sedgwick f
appearances are deceptive; and that at

that
the

Wight, part of ^ e
freshwater series is vertical, like the marine. Hefl ce
it is now ascertained that, as the chalk is horizontal a*

is vertical in the centre of that island, so the Eocene
strata are horizontal in the north of the island, and
vertical in the centre.

An important corollary is deduced from the dis-
covery above mentioned; namely, that the convulsion
which brought the Isle of Wight group into their V xe '
sent position were, in a great part if not entirely, s ub '
sequent to the deposition of the freshwater beds, ° r
upper members of the Eocene formation. They &$

* See Mr. Webster's section, Geol. Trans., vol. ii. ^
Series, Plate XI,

f Anniv. Address to the Geol. Soc., Feb. 1831, p. 9. ? t0 '
fessor Sedgwick informs me that his observations, made in 1 8g7
have recently been confirmed by Professor Henslow.

-,*

c h. XXII.

ELEPHANT BED, BRIGHTON.

261

owever, have been contemporaneous with those move-
ments which raised the central parts of the London
ari( l Hampshire basins to their present height. Re-
aring again to the diagram, Fig. 175. p. 258., we may
lln agine the series of elevatory movements in the S. E.
°f England to be divided into two parts : first, that
w hich casused the elevation and denudation of the
Antral axis of the Weald in A ; secondly, that which
gifted the denuded surface E, together with the
te *tiary formations d, to their actual height. Now,
^s last set of movements may have occured before
^e close of the Eocene period, and may have pro-
ceed that curve in the stratified rocks of the Isle
°f Wight, in which the freshwater beds there have

Participated.

At the same time great movements of elevation

av e been experienced in the south of England, at

^riods decidedly post-Eocene; as, for example, those

y which the crag strata attained their present posi-

lQl * in Norfolk, Suffolk, and Essex. The formation

als o called by Mr. Mantell the Elephant Bed, at the

°°t of the chalk cliffs at Brighton, is not merely a

J^us of calcareous rubble collected at the base of an

lr *land cliff, but exhibits every appearance of having

ee n spread out in successive horizontal layers by
*ate

The deposit alluded to skirts the shores between
r %hton and Rottingdean, and another mass appa-
* etl tly of the same age occurs at Dover. The pheno-
mena appear to me to suggest the following conclu

r in motion.

sions :

First, the south-eastern part of England had

Squired its actual configuration when the ancient
cll alk cliff A a was formed, the beach of sand and
^ngle b having then been thrown up at the base of

:' '

262

EOCENE PERIOD.

[Book

IV.

the cliff. Afterwards the whole coast, or at least that
part of it where the elephant bed now extends, s

Fig. 176,

A. Chalk with layers of flint dipping slightly to the south.
h. Ancient beach, consisting of fine sand, from one to four

feet

thick, covered by shingle from five to eight feet thick
pebbles of chalk-flint, granite, and other rocks, with br<* en

shells, &c.
t. Elephant bed, about fifty feet thick, consisting of layer*
white chalk rubble, with broken chalk flints, in which feP°
are found bones of ox, deer, horse, and mammoth.*

sided to the depth of fifty or sixty feet, and duri|#
the period of submergence successive layers of wh lte
calcareous rubble c were accumulated, so as to co* ei
the ancient beach b. Subsequently, the coast ^

again

■

* MantelPs Geol. of S. E. of England, p. 32.

f See MantelFs Geol. of S. E. of England, p. 32. Aft j*
re-examining the elephant bed in 1834, I was no longer in d<? u
of its having been a regular subaqueous deposit.

XXII.]

EXCAVATION OF VALLEYS.

263

■E

ocene alluviums.

The discovery, before men-
ded, of the genera Palaeotherium and Anoplotherium
^instead, associated with fossil shells of well-known
°cene species, is interesting, as showing that England,
r father the space now occupied by part of our island,
w ell as the country of the Paris basin, and Auvergne,

° c ene period, by a class of land animals of a very
P ec uliar type,
^t we have never found a single fragment of the
0tl es of any of these quadrupeds in our alluviums or

ant al, and Velay, were all inhabited, during the

<*ve bre

ccias. In these formations we find the bones

. ^e mastodon and mammoth, of the rhinoceros,

^popotamus, lion, hyaena, bear, and other quadru-

j^ s > all of extinct species. Where, then, are the

err estrial alluviums of that surface which was inha-

te d by the Paleothere and its congeners ?

At is difficult to answer this question ; but it seems

ear that a peculiar and rare combination of favour-

*bl

e circumstances is required to preserve mammifer-
or> indeed, any remains in terrestrial alluviums, in

*ss

^cient quantity to afford the geologist the means of

l gning the date of such deposits. For this reason

are scarcely able, at present, to form any conjec-

J- e a s to the relative ages of the numerous alluviums

lc h cover the surface of Scotland ; a country which

°bably became land long before the commencement

Ln e tertiary epochs.

Excavation of valleys.

eii referred chiefly to the ocean.

It will be seen that the
•vation of the valleys in the S. E. of England has

w ^hose geologists who contend that the valleys in
§*and are not due to what they term " modern
Se s," are in the habit of appealing to the fact, that

: i !

261

EOCENE PERIOD.

[Book

IV.

the rivers in the interior of England are working
sensible alterations, and could never in their presen
state, not even in millions of years, have excavate
the valleys through which they now flow. A &$ e
theory seems to be involved even in the term " modern
causes," as if it could be assumed that there wer
ancient causes, differing from those which are no^
operation. But if we substitute the phrase " exists
causes,"-* we shall find that the argument now contr

verted amounts to little more than this, — " that in
country free from subterranean movements, the act*
of running water is so trifling, that it could ne
hollow out, in any lapse of ages, a deep system
valleys, and, therefore, no known combination of e* 1
ing causes could ever have given rise to our prese

ve*
I

valleys !

iety

The advocates of these doctrines, in their anx
to point out the supposed absurdity of attributing
ordinary causes those inequalities of hill and & ?
which now diversify the earth's surface, have too oft
kept entirely out of view the many recorded examp
of elevations and subsidences of land during ea r
quakes ; the frequent Assuring of mountains and op
ing of chasms ; the temporary damming up of rivers
landslips, followed by their sudden and impet u °
escape ; the deflexion of streams from their orig lJ}
courses ; and, more important, perhaps, than all tb e \
the denuding power of the ocean, during the rise
continents from the deep* Few of the ordinary caUS ,
of change, whether igneous or aqueous, can be
served to act with their full intensity in any one p la
at the same time : hence it is easy to persuade *n
who have not reflected long and profoundly ° n

working of the numerous igneous and aqueous ag e

Ch - XXII]

RECAPITULATION.

265

*tt they are entirely inadequate to bring about any

lrtl Portant fluctuations in the configuration of the
e arth's surface.

Recapitulation. — I shall now briefly recapitulate
s °*ne of the principal conclusions to which I have
^rived respecting the geology of the south-east of
^ n gland, in reference to the nature and origin of the

— the two

Preceding chapters.

1. In the first place, it appears that the tertiary
str ata rest exclusively upon the chalk, and consist,
Wl th some trifling exceptions, of alternations of clay
at Ui sand.

2. The organic remains agree with those of the
*«ris basin ; but the mineral character of the English
te *tiary deposits is extremely different, those rocks in
Particular which are common to the Paris basin and
^ntral France being wanting, or extremely rare in

and.

3. The English Eocene deposits are generally con-
0r ttiable to the chalk, being horizontal where the beds

°* chalk are horizontal, and vertical where they are
Ver tical ; so that both series of rocks appear to have
Participated in nearly the same movements.

4. It is not possible to define the limits of the
Jteient borders of the tertiary sea in the south-east of
"7 n gland, in the same manner as can be frequently

0r *e in those countries where the secondary rocks are
^conformable to the tertiary.

5 - Although the tertiary deposits are chiefly confined

^ the tracts called the basins of London and Hamp-

lre > insulated patches of them are, nevertheless,

. Ul *d on some of the highest summits of the chalk

Evening between these basins.

v ol. iv.

111 II;

M^^^a^tt

266

EOCENE PERIOD

[Book

IV.

6. These outliers, however, do not necessarily pro^
that the great mass of tertiary strata was once conti-

nuous between the basins of London and Hampshire
and over other parts of the south-east of England W> w
occupied by secondary rocks.

7. On the contrary, it is probable that these secon
ary districts were gradually elevated and denuded
when the basins of London and Hampshire were s$*
submarine, and while they were gradually becoflifo£
filled up with tertiary sand and clay.

8. If, in illustration of this theory, we examine o$ e
of the districts thus supposed to have been denuded

decided proofe
that an immense mass of chalk and other secondly
formations has been removed by the force of water.

9. We may infer, from the existence in the We^

Weald

of large valleys along the outcrop of the softer be&
and of parallel chains of hills where harder rocks co& e

■

up to the surface, that water was the removing cause 5
and from the shape of the escarpments presented W
the harder rocks, and the distribution of alluvium? we
may also conclude that the denudation was success^

and gradual during the rise of the strata.

ded

10. The materials carried away from the denu
districts were probably conveyed into the depths of^ e
contiguous sea, through channels produced by & oS$
fractures which have since become river-channels, ^
which now intersect the chalk in a direction at rig* 1 *
angles to the general axis of elevation of the country*

11. The analogous structure of the valley of K^ s
clere, and of other valleys which run east and ^ est)
like the valley of the Weald, but are much narrower?
accords with the hypothesis, that they were all p r °'

•

Ch - XXII.]

RECAPITULATION.

267

fluced by the denuding power of water co-operating
Wl th elevatory movements.

12. The mineral composition of the materials thus
apposed to have been removed in immense abundance
fr °m the valley of the Weald, are such as would, by
^gradation, form the English Eocene strata.

13. The movements which threw the chalk and the
te niary strata of the Isles of Wight and Purbeck into
a vertical position, were subsequent to the formation
°f the Eocene freshwater strata of the Isle of Wight,
but may possibly have occurred during the Eocene
Period.

H. But some movements of land in the south of
** n gland must have been posterior to the deposition of
the crag ; and the ancient beach, together with the

elephant bed" at Brighton, seem to imply a subsi-
dence and elevation of comparatively modern date.

15. The masses of secondary rock which have been
e **ioved by denudation from the central axis of the

^eald would, if restored, rise to more than double the
!* ei ght now attained by any patches of tertiary strata
in England.

16. If, therefore, the Eocene strata do not appear to
c cupy a much lower level than the secondary rocks
r om the destruction of which they have been formed,

x s, perhaps, because the highest summits of the
ec ondary formations have been cut off during the rise
the land, and thrown into those troughs where we
n °^ find the tertiary deposits.

n 2

! \

268

CHAPTER XXIII.

FORMATIONS COMMONLY CALLED SECONDARY AND

TRANSITION.

Ancient and modern classification of fossiliferous strata

Form-
The di*

ations commonly called secondary and transition

- Sketch of th e

visions usually adopted not of equivalent value

principal groups — Cretaceous group (p. 271.) — No sp

e cies

common to the secondary and tertiary rocks — Chasm betwe
the Eocene and Maestricht beds — Duration of seconds ;
periods — Wealden strata — Their relation to the marine group
above and below — Portland " dirt bed" — Oolitic g r ° up
(p. 287.) — Lias — New red sandstone — Zechstein — Carbo^
iferous group — Old red sandstone — Transition formations^
Rock called Greywacke\

It was stated in a former chapter that the first r ud
attempt to classify rocks in chronological order ^ a
that according to which they were arranged in f° u
groups called primitive, transition, secondary, and t e
tiary — the transition and secondary comprising all tfl
stratified fossiliferous formations older than the terti&v'
These ancient divisions, although not yet obsol^ '
have gradually become less and less fitted to repress
the present state of our knowledge. It was n&? el
supposed that each of the four sections were of equ lV
lent importance, or, in other words, that they e&c
comprised a series of monuments relating to ^
portions of the ancient history of the earth. It wa . [
however, imagined that they followed each other

■

Ch - XXIII.]

CLASSIFICATION OF STRATA.

269

re gular chronological order, and that the primary were
Wways older than the transition; that the transition
w ere more ancient than the secondary, and the second-
ly than the tertiary strata. That this opinion, though
generally correct, is not strictly true in regard to the
ei *tire series called "primary," whether stratified or
^stratified, will appear in the sequel.*

The fossiliferous strata have been variously grouped,
a ccording to the comparative value which different
geologists have attached to different characters ; some
having been guided chiefly by the thickness, geogra-
phical extent, and mineralogical composition of par-,
ticular sets of strata ; others, by their organic remains.
AH, however, seem now agreed that it is by a com-
bination of these characters that we must endeavour
to decide which sets of strata should be entitled to
r &nk as principal or independent groups. The fol-
lowing is an outline of the arrangement adopted in
this work, which will be more fully explained by the
Tables at the end of this and the 27th chapter :

1. Tertiary, or supracretaceous f

2. Cretaceous

Tertiary.

3. Wealden

4. Oolite, upper, middle, and lower

5. Lias -

6. New red sandstone and muschelkalk

7. Magnesian limestone and zechstein

8. Carboniferous -

9. Old red sandstone - -

r Secondary

Chap xxvii.

t For tertiary, Mr. De la Beche has used the term " supracre-
ta ceous," a name implying that the strata so called are superior
ln Position to the chalk.

N 3

;

270

CLASSIFICATION OF STRATA.

[Book

IV.

10. Ludlow rocks

11. Wenlock limestone
J 2. Caradoc sandstones

13. Llandeilo flags

14. Fossiliferous Greywacke

1 Upper

unan

JSil
1 Lower

J Silurian*

Transition-

The third group, however, of the above list, or the
Wealden formation, although locally of great thickness
in the south-east of England, is so partial a deposit
that some geologists think it should be merged in the
oolite, others in the cretaceous system; to both °f
which propositions there are objections, as will after-
wards appear. The fifth group, or lias, would by roan?
be included in the oolites. The old red sandstone has
usually been classed as the lower part of the carboni-
ferous series ; but the fossils recently found in it are
so distinct from those of the coal, and, on the other
hand, from those of the underlying Ludlow rocks, that
it seems fairly entitled, on these grounds as well as
from its great thickness in parts of England and Scot-
land, to stand as a separate section.

Among other objections to the above classificatio n
it may be said that the tertiary group, comprehending
all the deposits from the Eocene strata to the NeW er
Pliocene inclusive, is of greater importance than ma ?
of the other divisons. It may also be suggested that
the oolitic formation might admit of three subdivisions*
each as much entitled to rank as an independent for&*
ation as the lias. The following would, perhaps, be »
nearer approximation to an arrangement in which the
leading divisions would be of equivalent value, as esti-
mated by the successive changes in organic life impli e(J
by the imbedded fossil remains and by the geographic 1
extent and thickness of the strata :

* For explanation of the term " Silurian/' see p. 29$.

Ch - XXIII.]

*• Plioce
2.

3.
4.
5.
6.

7.
8.

10.

CRETACEOUS GROUP.

271

ne.

11. New red sandstone and

Miocene.

■

Muschelkalk.

Eocene.

12.

Magnesian limestone

Maestricht and Chalk.

Zechstein.

Green sand.

13.

Carboniferous formatk

Wealden.

14.

Old red sandstone.

Upper Oolite.

15.

Ludlow rocks.

Middle Oolite.

16.

Wenlock limestone.

Lower Oolite.

17.

Caradoc sandstone. \

Lias.

18.

Llandeilo flags.

and

19. Fossiliferous Grevwacke*.

It is not my intention to enter at present upon a
^tailed description of the fossiliferous formations older
^an the tertiary, the elucidation of which might well
^cupy another volume. The observations about to be
°Sered have chiefly for their object to show how far the
r ules of interpretation adopted for the tertiary form-
at ions are applicable to the phenomena of the older

* *

^dimentary rocks. -

PRINCIPAL GROUPS. {Descending Series.)

Cretan

Strata from the Chalk ofMc

tricht to the Lower Green-sand inclusive. — F, Table I.

p. 302.

The principal subdivisions of this group, as it occurs
^England and in several countries of the North of
Europe, will be found on consulting Table I. Group F.
*hey are six in number, namely; — 1. the Maestricht
beds, — 2. the chalk with flints, — 3. the chalk without

flints,

4. the upper green-sand, — 5. the gault,

P* the lower green-sand. The newest of these deposits

is well

Mount, M

Mon

of " England and France. It is a soft yellowish stone,
**ot very unlike chalk, and " includes siliceous masses,

n 4

272

CRETACEOUS GROUP.

[Book IV

which are much more rare than those of the chalk, of
greater bulk, and not composed of black flint, but of
chert and calcedony."*

It is characterized by a peculiar assemblage °f
organic remains, perfectly distinct from those of the
tertiary period. M. Deshayes, after a careful compa-
rison, and after making drawings of more than two
hundred species of the Maestricht shells, has been
unable to identify any one of them with the numerous
tertiary fossils in his collection. On the other hand
there are several shells which are decidedly common
to the calcareous beds of Maestricht and the white
chalk ; as, for example, the twelve following species, o*
which the names have been communicated to me by
M. Deshayes : — Catillus Cuvieri (Fig. 177.) (sp e *

Fig. 177

•>

Catillus Cuvieri. Syn. Inoceramus Cuvieri, Sow. Chalk withfl int$ '

(Fig

P. Hoperi (Fig. 179.), Pecten fragilissimus, Ostrea ve*

), O. carinata (Fig. 182.)

Fig. 178

Fig. 179.

Fig.

Crania Par isiensis,

inferior or attached
value.

Plagiostoma
Hoperi.

Ptogiostoma

spinosum. $

Fitton, Proceedings of Geol. Soc. 1830.

Ch « XXIII.

]

MAESTRICHT BEDS.

273

Pa Hsiensis (Fig. 178.), Terebratula octoplicata (Fig

Pio-. 1QI !?• ,r,~

g- 181.

Fig. 182

T^ebratula
Uefrancii.

Ostrea carinata,
characteristic of Upper Green-sand.

°3.), T. carnea (Fig. 185.), T.pumilus (Magas, Sow.)

Fl *g 185

Fig. 184. Fig. 185.

Terebratula
octoplicata

ar - of T. pUcatili*-)

Terebratula pumilus.
{Magas pumilus, Sow.)

Terebratula
carnea.

(*i*.

),T.Defrancii(Fig.l81.)

)

Maestricht

^ely into the white chalk of the French geologists,

^ mto their " chloride, or green-sand," which corre-

P°nds with the upper green-sand of the English geolo-

s st s. The following five species of shells have been

c °gnized by M. Deshayes as common to the Maes-

l cht beds and the upper green-sand of France : —

a giostoma spinosum (Fig. 180.), Ostrea vesicularis

Fig. 1 86

Ostrea vesicularis {Gryphcca globosa, Sow.)

N 5

27*

CRETACEOUS GROUP.

[Book &

Fig. 187,

Fig. 188

a. Belemnites mucronatzis.
o. Same, internal structure

Fig. 1 89,

Baculites Faujasii.

Baculites anceps\ Chalk.

(Fig. 186.), O. carinata (Fig. 182.), Belemnites mucr^
natus (Fig. 1S7»)> and Baculites Faujasii (Fig. 188-/;
Count Munster has shown me, among the f° sSl
which he himself collected at Maestricht, three spe# e

of ammonite, among which is A. Rhotomag

.gfiffif

Fig. 190

(Defrance) ; also a specie 3
Hamite, and Hippurites D 6 ^
moulinsi (Golf). The s

Ammonites Rhotomagensis, all of

eminent naturalist has d& c
vered no less than forty s ? .
cies of microscopic for* 35
nifera in the same forma* 1

species distinct * r ,

new genera

any known either as recent or tertiary, and many

There is also an ammonite, obta in #
from the Maestricht limestone by Dr. Fitton, no^
the museum of the Geological Society of LoB au t ,
The occurrence of these ammonites and specif
kindred genera, such as the Baculite and Hamite
also the Belemnite, is important, as showing that
subdivision (No. 1.) now under consideration sn°
be classed as the newest member of the second

, rather than as a link between it and the
tiary. No shell hitherto found, even in the oldes

series

Ch ' XXIII.

]

CHALK.

275

°eene tertiary formations, minutely as these have

ee n investigated, could be mistaken, either for the
at ^tnonite or belemnite, the nearest approach to the
ar **monite being the nautilus, and the tertiary fossil

hich comes nearest to the belemnite being the
Ke loptera of the London and Paris basins (Fig, 191.).

%. 191.

**m

We can scarcely expect, therefore,
to discover in existing tropical seas
any living representatives of those m
curious cephalopoda, ammonites and
belemnites, which evidently swarmed
in the ocean when the cretaceous
and many preceding groups of strata

^Wera beiemnitoidea, were formed. They even seem to

°^» and Parts basins, have become entirely extinct, at

e ^st in European latitudes, before the commencement

°^ the Eocene period.

The rock commonly known as chalk preserves its
^culiar mineral character throughout a considerable
ai " e a in Europe, but it is rarely of such thickness as in
^y parts of the south-east of England, where hori-
? °itally stratified masses about one thousand feet
l ^ck 3 are composed of it. Its upper member in this
c °Untry is usually called the " Chalk with flints ; " but
a We this mass there is in some places another de-
Nit of white chalk without flints, which was found, by

ting at Diss, in Norfolk, to attain a thickness of

lQ feet.

* The chalk stretches over a large part of

■

° Ur island, and recurs in the north of Ireland, is found

!? Denmark and the south of Sweden, and even in

°W and part of Russia. In France it surrounds

^ underlies the strata of the Paris basin before de-

* Proceedings of Geol. Soc, vol. ii. p. 93

N 6

■

•

276

CRETACEOUS GROUP.

[Book &•

(see Map, Fig. 156. p. 209.)

stretches northward into Belgium and the north of
Germany, and southward to the basin of the Gironde-
I have seen it, still retaining nearly all the same cha-
racters, between Bordeaux and Dax ; but it change*
its aspect greatly on the flanks of the Pyrenees, where
its identity can only be established by the similarity
of its fossil remains. Even the white chalk, however?
varies considerably in its texture, in proportion as * e
depart from the great central deposit of Europe. & 1
some parts, for example, of the south of France, lt
becomes oolitic. Here also it contains, together wit* 1
shells which abound in the north, many other specie^
peculiar to more southern districts, especially of & e
genera spherulite, hippurite, and nummulite.*

Fig. 192.

a, Hippurites bioculata, Lamk.

prf*

The other divisions of the cretaceous group, Nos-^
5, and 6., consist of sands and clays, which have d s °
a wide geographical range. The position of the g^ ult
**d lower green-sand, relatively to the formations ot

the white and flinty chalk before alluded to, has bee* 1
elucidated in diagram Fig. 157. p. 224. The fo$$ S

Fig. 193.

Fig. 194.

a. Terebratula lyra. 7 TT Pecten 5 c ?\ n n&

b. Same, seen in profile, j U PP er green-sand. v er a nd 10 ,

green-s^ 1

Dufrenoy, Bulletin de la Soc. Geol. de France, torn. i. P- *

Ch - xxm.

CRETACEOUS GROUP.

277

Fig. 195.

Q> Turrilites costatus, Gault.

6. Same, shewing the indurated border of the partition of the chambers.

°f the inferior arenaceous and argillaceous groups are
u Pon the whole very different from those of the chalk
Wore described, but there are many species common
to these two great divisions.

The testacea obtained from the entire cretaceous
Astern amount to about one thousand ; and if, for the
Sa ke of classification, we refer every set of strata in
Europe which are characterized by these organic re-
gains to one period, we immediately comprehend in
11 rocks of every variety of mineral composition, yet
^hich always occupy a determinate place in the order
°* superposition intervening between the tertiary strata
ari d those of the Oolitic period.

In the cretaceous group, thus distinguished, we
^hold in the Pyrenees and in Spain compact and
Cr ystalline marbles, masses of gypsum and salt, pud-
^ n gstones, red sandstone, thin shales and grits, con-
fining impressions of marine plants, and other rocks,
to which there is nothing analogous in formations of
^e same age in northern Europe.

•

Morea

° c curs, composed of compact and lithographic lime-
stones of great thickness ; also of granular limestones,
Wlt h jasper ; and in some districts, as in Messenia, a
Puddingstone with a siliceous cement more than 1600
fe et in thickness.*

* Bull, de la Soc. G£ol. de France, torn. iii. p. 149.

■i

278

CRETACEOUS GROUP,

[Book

IV.

It is evident, observe these geologists, from the great
range of the hippurite and nummulite limestone, a rock
belonging to the same era, that the South of Europe was
occupied at the period of the cretaceous depositions
by an immense sea, which extended from the Atlantic
Ocean into Asia, and comprehended the South °*
France, together with Spain, Sicily, part of Italy, and
the Austrian Alps, Dalmatia, Albania, a portion ot

the Troad.

JEgea

The plants found in the chalk of England and France
are chiefly marine. Some wood has been occasionally
met with, both in the chalky rock and its flints, having
the appearance of being drifted, and commonly marked
with the perforations of boring shells, such as the
Teredo and Fistulana.* In Sweden, M. Nilsson has

found beds of lignite associated with our common
chalk fossils f; so that we may conclude that forests
grew on the lands of this period, wherever these may
have been placed ; but as yet their site is mere matter
of conjecture.

The testacea, zoophytes, Crustacea, and fishes, are
marine, and no bones of mammiferous quadruped 5
or birds have yet been discovered ; but in the Maes*
tricht beds large turtles have been found, and a
gigantic reptile, the Mosasaurus, or fossil Monitor, of
Maestricht, some of the vertebrae of which app ear
also in the English chalk. :£ The osteological charac-
ters of this oviparous quadruped prove it to have been
intermediate between the living Monitors and Iguanas ;
and, from the size of the head, vertebrae, and othe r

* Mantell, 6eol. of S. E. of England, p. 96.

t Petrificata Suecana, 1827.

f See MantelPs Geol. of S. E. of England.

Ch - XXIIU

. MAESTRICHT FOSSILS.

279

hones, it is supposed to have been twenty-four feet in

fength.
In reviewing the facts above enumerated, I may first

C &U attention to the important circumstance that no
species of fossil shell has yet been found common to
the secondary and tertiary formations ; a fact stated on

tertiary

Posed by some geologists to be intermediate between
the secondary and tertiary formations. On the other
hand some of the most characteristic species of
Cfosau occur in the green-sand beneath the chalk, at

Ciply,

Mons, in Belgium, and at some

Neighbouring places which I have visited. Count
funster also informs me, that the zoophytes which
he possesses from the Gosau beds differ specifically
fr om any which he knows as tertiary. I mention this
h* the hope that the identifications which have been
^ade of Gosau and tertiary species may be re-examined
w «h scrupulous care, for, if confirmed, they would be of
the greatest theoretical interest.

This marked discordance in the organic remains of
the two series is not confined to the testacea, but
e *tends, so far as a careful comparison has yet been
instituted, to all the other departments of the animal
kingdom, and to the fossil plants. Dr. Agassiz, whose
§ r eat work on fossil fish is now in progress of publi-
cation, has discovered no species of fish common to
the secondary and tertiary rocks.

There appears, then, to be a greater chasm between
the organic remains of the Eocene and Maestricht
^ e ds, than between the Eocene and Recent strata;

* there are some living shells in the Eocene form-
ations, while there are no Eocene fossils in the newest

1 :

«**v~.

280

WEALDEN STRATA.

[BooK

IV.

secondary group. It is not improbable that a longe r
interval of time may be indicated by this greater
dissimilarity in fossil remains. In the 3d and 4th
chapters I endeavoured to point out that we have no
right to expect, even when we have investigated a
greater extent of the earth's surface, that we shall be
able to bring to light an unbroken chronological series
of monuments from the remotest eras to the present ;
but, as we have already discovered a long succession
of deposits of different ages, between the tertiary
groups first known and the recent formations, so we
may, perhaps, hereafter detect an equal, or even
greater, series intermediate between the Maestricht
and Eocene strata.

The different subdivisions of the cretaceous group
(No. 1.), extending from the chalk of Maestricht to
the lower green-sand inclusive, may, perhaps, relate
to a lapse of ages as immense as the united tertiary
periods, of which the eventful history has been
sketched in this work. Such a conjecture, at least?
seems warranted, if we can form any estimate of the
quantity of time, by comparing the amount of vicis*

situde in animal life which has occurred during lts
lapse.

2. The Wealden, or the Strata from the Weald Clay &
the Purbeck Limestone inclusive.— G, Table I. p. $$"

It will be seen by the Table I. p. 302., that in the
South of England this group may be divided into three

formations

Weald

the Purbeck beds, which are all characterized by the
remains of freshwater animals ; whereas the cretaceous
strata which are superimposed unon the Wealden, >°

Ch ' XXIH.

]

WEALDEN STRATA.

281

e south-east of England, contain fossils of marine
Secies.*

The position of these beds has been indicated in

a gram Fig. 157. page 224., and the map (Plate XV.)
w, tt show the superficial area occupied by them in
^ en t, Sussex, Surrey, and Hampshire. It must not
e supposed, however, that they terminate at the
Points where they happen to be covered by the creta-
Ce °us system. The same group has been ascertained

extend from west to east (from Lulv

)

n gHsh miles; and from north-west to south-east
(from Whitchurch to Beauvais), 220 miles ; the depth
0r total thickness of the beds, where greatest, being
a bout 2000 feet.f The general appearance of the
c ' a ys and sands, and of the subordinate beds of lime-
st °ne, grit, and shale, and of the imbedded shells,
* ec alls so precisely that of many tertiary formations of

re shwater origin, that it is only after having deter-
^ ln -ed the species of organic remains that we recognize
a discordance in character as great as might have been
atl ticipated when strata above and below the chalk

er e compared.

The vegetable remains belong, some of them, to

Wtoits which appear to have held an intermediate place

stween the Equiseta and Palms, as the Clathraria

**b

Mantell

descent ferns, the species being very peculiar, and
!* ot known in any other deposit, whether of higher or

l *tfe

ior antiquity. J

The term Wealden was suggested by Mr. Martin, and will
*°Und of great convenience,
t Pitton's Geol. of Hastings, p. 58.
t Mantell, Geol. of S. E. of England, chap. xi.

*<?

' -I ■

282

WEALDEN STRATA.

IV.

[Book

The shells of the Wealden are almost exclusively
fluviatile ; and, as is usual in assemblages of freshwater
testacea, a few species only are found, while the if
dividuals are very numerous, sometimes forming the
principal component of entire beds of limestone. Shell*
of the Cypris, also, a freshwater animal, befo re
mentioned as occurring in the lacustrine deposits oi
Auvergne, are profusely distributed throughout W e
Wealden. Of this genus several species have bee»

discovered, named and figured by Dr. Fitton.

(See

)

Fig. 196.

Fig. 197.

Fig. 1 98.

#--

Cypris
spinigera,
Fitton.

Cypris Valdensis, Fitton.
(C.faba, Min. Con. 485.)

Cypris tuber^ atff
Fitton.

Some fish, also, of forms resembling known fluvia^
genera, have been met with; but the remains ° t
reptiles present the most remarkable feature in ^ ]lS
group. Some of these belong to turtles, such as ^
Trionyx, a genus now occurring in freshwater in tr °"
pical regions: others are referable to the genus V&P 9
Of Saurian lizards there are at least five genera; & e
Crocodile, Plesiosaur, Megalosaur, Iguanodon, an
Hylaeosaur. The Iguanodon, of which the rem^
were first discovered by Mr. Mantell,was an herbi* '
rous reptile, and was regarded by Cuvier as more &
traordinary than any with which he was acquaint^'
for the teeth, though bearing a great analogy to tlie

See Trans, of Geol. Soc, vol. iv., Second Series, now io

the

press

Ch - XXIH.

WEALDEN STRATA.

i* ••» — —

283

Modern Iguanas which now frequent the tropical

striki

West

^ing and important differences. It appears that
e y have been worn by mastication ; whereas the
listing herbivorous reptiles clip and gnaw off the
Setable productions on which they feed, but do not
e w them. Their teeth, when worn, present an ap-
^arance of having been chipped off, and never, like
* e fossil teeth of the Iguanodon, have a flat ground
SUf face, resembling the grinders of herbivorous mam*
^li a> * p rom the large bones, found in great num-
r s near these teeth, and fairly presumed to belong

!° the same animal, it is computed that the entire
etl gth of this reptile could not have been less than
Sev entyfeet.

Wealden

in no part has any fragment of the skeleton of a
^tniferous quadruped been obtained. With this
e * c eption, to which I shall presently revert, the strata
I the Wealden present such characters as we might
°°k for in the deposits of the deltas now forming at
e mouths of large rivers in tropical climates.
. The Wealden, as was before explained, is covered

^ the marine cretaceous system, and reposes upon
a *oth

e P°sit ; namely, the uppermost member of the Oolite,

°* group H, Table I. p. 303.

i This intercalation of a great freshwater formation

^tw een tWQ ot h ers f marine origin is a remarkable

er, which is, in like manner, a purely marine

ct > and attests, in a striking manner, the great extent
former revolutions in the position of sea and land.
n those sections where the junction of the freshwater
cretaceous system is seen, the beds of the lower

Mantell, Geol. of S. E. of England, p. 277

■ I ■

284

PORTLAND DIRT-BED.

[Book

green-sand have been observed to repose conformably

Weald

There is »°

IT , j~^v/**v i t vuxu way. «j.x*w*~

indication of disturbance : " To all appearance tb*
change from the deposition of the freshwater remai^
to that of the marine shells may have been effect
simply by a tranquil submersion of the land to a grea^

of tb*

depth beneath the surface of the waters." *

At the point of contact of the inft
Wealden or « Purbeck beds," with the more ancte n *
marine system, a very curious phenomenon is observe" •
the freshwater calcareous strata repose, both in P° ft '
land and Purbeck, upon the oolitic limestone, call e
the Portland stone, which abounds with Amnionic 8 '
Trigoniae, and other marine shells. Between the tflr0
formations there intervenes " a layer, about a foot
thickness, of what appears to have been an and e
vegetable soil ; it is of a dark brown colour, contain
large proportion of earthy lignite, and, like the xao^
soil on the surface of the island, many water-^° rJl

stones. This layer is called the < dirt-bed ' by
quarrymen ; and in, and upon it, are a great nui»b e '

tb«

lb*

of silicified trunks of coniferous trees, and plants a
to the recent cycas and zamia. Many of the sten^
the trees, as well as the plants, are still erect, as

petrified while growing undisturbed in their »a
forest ; the trees having their roots in the soil, ^
their trunks extending into the superincumbent fitr**

aatf

Is"

Traces of this vegetable earth, occupying the s

* Dr. Fitton, Geol. of Hastings, p. 28.

f Mantell, Geol. of S. E. of England, p. 336. — See
papers by Mr. Webster, Dr. Buckland, and Mr. De la $ e ' '
Geol. Trans., Second Series, vol. ii. Mr. Webster was, I » elieV '
the first to notice the erect position of the stems.

Ch.

XXIII.]

PORTLAND DIRT-BED.

285

e '&tive situation, have been observed by Dr. Fitton in
^ e cliffs of the Boulonnois, on the opposite coast of
* r ance. * Dr. Buckland and " ^ ' " ' a

So ascertained that many of the stumps of trees re-
gain erect, with their roots attached to the black soil
? n ^hich they grew, their upper part being imbedded
111 the limestone ; from which they infer, " that the

*Urf,

% l ***e dry land, and covered by a forest, and probably

* a climate such as to admit the growth of the modern
Za *maandCycas."f

It seems a legitimate deduction from the data above
^Plained, that the marine formations of an antece-

ace of the subjacent Portland stone was for some

(that

oolite) had become land

0l tth of England, and the opposite coast of France ;

^ that this land then sank down, with its forests, and

, ec &me submerged beneath the waters of a great river,

. st as the region around Sindree, in Cutch, subsided

11 1819 ? and was permanently laid under water, being

^ 0ri e time occupied by the fresh water of the Indus. J

^country may then have continued to subside, until

Sickness of one or two thousand feet of fluviatile

e ^iment had been gradually accumulated; and this

e Posit, or delta, by a continuation of the same de-

J* e ssing operations, may, in its turn, have become

Ur *ed deep beneath the sea in which the chalk was

r med.

^ shall not enter farther into these speculations at

Wealden

Connected by its fossil remains with the overlying or

Geol. of Hastings.

Geol. Proceedings, vol. i. p. 9.
t Proceedings of Geol. Soc, April, 1830.
* See Vol. II. p. 196., and Vol. III. p. 254., and Plate V.

286

WEALDEN STRATA.

" -'.

[Book

subjacent formations. First, we may ask whether the*
are any species of fossil animals or plants common
the freshwater group and to the oolitic system. I a
aware of one example only, the Megalosaurus Bitf
landi; for the teeth and bones of this great saur*

occur in the btonesheld oolite and the Hastings s***
the remains in both cases having been referred J
Cuvier to the same species. There are also s 0lP
generic forms both of reptiles and fish common to
Oolite and Wealden, and not yet discovered in the cha
Vertebrae, for example, of the Plesiosaurus are **

in the Wealden ; and the Lepidotus, a genus

confined to the oolite and lias, but have been also fi> u

very characteristic of the Wealden, is unknown in * ,
cretaceous group, while it is abundant in the oo»

On the other hand, the same Iguanodon M a

... . rt .* . .1 TIT J\Ap&1

series.

telli, which is so conspicuous a fossil in the Wea
has recently been discovered near Maidstone
overlying Kentish rag, a marine limestone of

tha*

lower green-sand. From this fact we may infer
some of the saurians which inhabited the country

A W&

that great river, which by its sediment produced
Wealden strata, continued to live when part of
country had become submerged beneath the sea. *
in our own times, we may suppose the bones of * a *
alligators to be frequently entombed in recent fr e r

water strata in the delta of the Ganges. But if p
that delta should sink down so as to be covered by
sea, marine formations might begin to accumulate in
same space where freshwater beds had previously &
formed ; and yet the Ganges might still pour do^n
turbid waters in the same direction, and carry *
carcasses of the same species of alligator to the sea?

Ch.

XXlii.]

OOLITIC GROUP.

287

hl ch case their bones might be included in marine
^ell as in subjacent freshwater strata.
Near Beauvais, in France, there is a small valley of
v ation and denudation, closely resembling in struc-
Ure that of the Weald, and called the country of Bray,
w here the green-sand crops out from beneath the chalk,
^d where strata, for the most part like those of the
^ e alden, appear beneath the green-sand. One mem-
f r of the series, a fine whitish sand, contains impres-
ts of ferns, considered by M. Adolphe Brongniart
^ s identical with Lonchopteris Mantelli, a plant found
re quently in the Weal den. I examined part of the
^'ey of Bray in company with M. Graves, in 1833,
^ I observed that the sand last mentioned, with its

Stable remains, was intercalated between two sets

of
f Marine strata, containing trigonise, and referred, by

r erich geologists, to the lower green-sand. In the
ar **e country of Bray, and associated with the same
Nation, is a limestone resembling the Purbeck mar-
.. e > and containing a Paludina which seems specifically
ic,e ntical with that of Purbeck.
*here are some few species, therefore, of the Weal-
etl common on the one hand to the overlying Creta-
ns group, and on the other to the subjacent oolite ;
^ the connection hitherto established is so slight
at the era of the freshwater deposit may have been
Parated by a wide interval of time from the periods
^ the animals either of the oolitic or cretaceous
^iods predominated.

■

288

OOLITIC GROUP.

[Book

IV.

3. Oolite, or Jura Limestone Formation. — H, Table if

p. 303.

The different subdivisions which have been made W'

land

the classification of the rocks of this group in Eng
are enumerated in Table I. p. 303. It consists
limestone, clay, marl, and sand ; which, considered l
the aggregate, retain the same lithological characte

Germany. It is not to be expected that we sho u
be able to follow the different members of the Eng' 1

throughout a considerable part of England, France, ^

both

or* 6

series throughout Europe, as they vary greatly?
in mineral and organic characters, in their cO
throughout different parts of our own island ; but? .
the fossils of the higher, middle, and lower parts
the series are not the same, it may be possible? *

their aid, to establish subordinate groups of %
utility.

Among the fossils known to have a wide rang 6

Europe, and peculiar to the upper division,

I tftf

mention Gryphcea virgula, as occurring in France, ne

Fig. 199.

Fig. 200.

Gryphcea
virgula. A

Oxford, and elsetfh^
(Fig. 199.), and 0*"
deltoidea (Fig. 20°^
common in part ot

Ostrea deltoidea.

upper Oohte or *
/ meridge clay, thro«g»
out England and ,
north of France, a

found also in Scotland, at Brora.

The coral rag of England, and analogous zoophy tl f
limestones of the oolitic period in different parts
Europe, bear a resemblance to the coralline formati° p
now in progress in the seas of warmer latitudes.

°h. XXIII.]

p ig. 201.

OOLITIC GROUP.

289

A member of the oolite of the Jura,
corresponding to part of the English
coral rag (H. 3. Table L p. 303.), has
been called « Nerinsean limestone "

(Calcain
Nerincea

) by M

~ w — **j

much resembling the Cerithium in ex-

ternal form.

(Fig

201.) of one from the coral rag shows
the curious form of the hollow part of
each whorl, and also the perforation

Section of Nerincea , „ „

hieroglyphics which passes up the middle of the co-

Coral raer. .

lumella.

Fig. 202.

Cast of Dicer as arietina.
Coral rag.

A division of the oolite in the
Alps, referred by most geologists
to the coral rag, has been often
named " Diceras limestone," or
Calcaire a Dicerates," from its
containing abundantly a bivalve
shell (Fig. 202.) of a genus allied to
the Chama.

In the lithographic limestone of Solenhofen, belong-
In g to one of the upper members of the series, a great
Va riety of organic remains is found. Among these I
have seen in the museum of Count Munster no less
tn an seven species of flying lizards, or Pterodactyls, six
Brians, three tortoises, sixty species offish, forty-six
of Crustacea, and twenty-six of insects. The number
ot testacea is comparatively small, as also of plants,
hich are all marine. Count

^7 species of animal and vegetable remains from the
^°lenhofen slate when I saw his collection in 1833.

Munster

e extreme fineness of the sediment has, in this

Stance, allowed impressions of some of the most

V OL. IV.

1 u ; !

•

290

LIAS.

[Book

IV.

delicate and soft parts of various animals to be \>* e '
served ; as of the belemnite and several insects.

In the Stonesfield slate (see Table), the remains of
reptiles have been found associated with marine shells?
and with them the jaws of at least two species of smal 1
mammiferous quadrupeds of a genus allied to the
Didelphys, or Opossum. * It is very remarkable, that
these fossils afford the only exception yet known to
the apparent absence of all terrestrial mammalia fro** 1
the islands and continents which existed anteriorly t0

the Eocene period.

Among the characteristic shells of the oolite I may

instance Terebratula spinosa (Fig. 203.), Pholadom^

fidicula (Fig. 204.), and Belemnites hastatus, (Fig.205->

Fig. 203.

Fig. 204.

Terebratula spinosa.
Inferior Oolite.

a. Pholadomy a fidicula. Inferior Oolite.

b. Heart-shaped anterior termination of the sctflM'

Fig. 205.

Belemnites hastalus

4. Lias. I., Table I., p. 304.

The English provincial name of Lias has been vet;
generally adopted for a formation of argillaceous \i& e
stone, marl, and clay, usually found in conformao
stratification to the rocks of the oolite group before d e *
scribed. Some geologists regard the lias as the \o^ eS
member of the oolite group, several species of orgafl

* For figures of these, see above, Vol. I. pp. 237, 238.

Vh XXIII.]

LIAS.

291

remains being common to it apd to the inferior oolite.
If we draw a line between these formations, the sepa-
ration will be somewhat arbitrary, but may be, never-
theless, convenient ; as both the oolite group and the
Has will still cgmprehend a great thickness of strata,
characterized, when viewed on the great scale by
a ssemblages of distinct fossils. The lias retains a uni-
form mineralogical character throughout a great part of
England, France, and Germany; and this circumstance
^ay facilitate the attempt to ascertain the contempo-
raneous existence of a sufficiently numerous set of fos-
Sl l plants and animals to enable us to determine the
e quivalent groups of distant countries.

A principal member of this formation has been
sometimes called on the Continent " Calcaire a gry-
Pfytes," or " Gryphyte limestone/' from the great
abundance of a species of shell of a genus allied to

Fig. 206.

Fig. 207.

&r$pheea incurva, Sow.
&yn. G. arcuata, Lam*

the oyster

Nautilus truncatus. Lias.

(See Fig. 206.)

The remains of reptiles, those of saurians in par-
ocular, are very common in the liassic rocks in several
Parts of England, especially of the genera Ichthyo-
Sa urus, Plesiosaurus, and Crocodile.

The fish are, for the most part, of the same genera

as in the oolite. (See Figs. 208, 209.).

o 2

292

NEW RED SANDSTONE

[Book

IV.

Hybodus reticulatus. Lias, Lyme Regis.

a. Part of the fin, commonly called Ichthyodorulite.

b. Tooth of the same.

Fig. 209.

■

Acrodus nobilis, tooth ; commonly called fossil Leach.

Lias, Lyme Regis, and Germany.

(

Muschelkalk of the Germans)

"•«.

■

The deposits which are referable to the interval
which separated the lias from the great coal formation
may be divided into two principal groups : first, the
New Red Sandstone ; secondly, the Magnesian Lime-
stone. The New Red Sandstone of England, accom-
panied by beds of gypsum and rock salt, is almost
entirely destitute of organic remains ; but the Muscn*
elkalk of Germany, which is referable to the same
period, and has no precise equivalent among the Engh s
strata, contains many fossils of species distinct fro** 1

■■

Fig. 210.

a. Avicula socialis. b. Side view of same.

Characteristic of the Muschelkalk.

those of the lias, or subjacent magnesian limestone.

Ch. XXIII.]

MaGNESIAN limestone

293

(Muschelkalk)

posed in Bavaria and Wurtemburg, between two others;
the overlying " Keuper," or variegated marls, with
which it alternates at the junction, and the red mottled
sandstone (" bunter sandstein") on which it rests.
The plants found by Count Munster in this last, and
in the " Keuper," are so similar, as to induce that geo-
logist to regard all the three groups thus connected
as belonging to one period ; and in confirmation of the
same opinion, M. Agassiz finds the same species offish
to be common to the three groups.

6. Magnesian Limestone (Zeckstein of the Germans).

L., Tab. I., p. 305.

This formation consists in England for the most
part of a yellowish limestone, in which a small number
only of organic remains are preserved, but these are
deferable to peculiar and characteristic species.

So also in the zechstein of the Germans, a limestone
of this period, and in its accompanying copper slate,
the same or very similar fossils occur. At
^ Upper Saxony, for example, fish are found of the
extinct genus Palaeothryssum, only known in strata of
this group. Dr. Agassiz informs me that he has not
as yet been able to identify any species from Mansfeld
with any one of those found in England, but the genus
. appears characteristic of the era under consideration.

^ Carboniferous Group > comprising the Coal-measures,
and ike Mountain Limestone. M., Tab. I., p. 305.

The rocks of this group consist of limestone, shale,
sandstone, and conglomerate ; interstratified with which
a re large beds of coal, a substance now universally
admitted to be of vegetable origin. Several hundred

o 3

Mansfeld

' \

294

CARBONIFEROUS GROUP.

[Book 1^

fr"

species of plants have been found in the shales and
sandstones associated with the coal, and all are, witfe
few exceptions, of species differing widely from those
which mark the vegetation of other eras. Some re-
marks have been offered in the first book *, respecting
the known geographical extent of the coal formation
and the tropical character of its flora, and of the shell*
and corals of the carboniferous or mountain lime*
stone.f I there adduced arguments for inferring that
the lands in northern latitudes consisted, for the most
part, at that remote era, of small islands ; and men-
tioned the absence of large saurian remains, the insula
character of the flora, and the deposition of the strata?
as favouring that opinion.

But although the higher latitudes of the northern
hemisphere probably formed at that time a great archi*
pelago, they must have contained some islands of sufr
cient magnitude to allow of the existence of rivers?
and estuaries, where freshwater strata were accumu-
lated. A freshwater limestone has been discovered
and described by Dr. Hibbert at Burdiehouse near
Edinburgh, as lying beneath marine strata of the car*
boniferous group. Instead of containing fossil coral*
lines or encrinites, like the mountain-limestone, the
formation in question contains land plants in great
abundance, and minute entomostraca supposed to b e
allied to the genus Cypris and several fish.^

Mr. Hutton states that, in part of the coal-field of
Northumberland and Durham, fossil shells of a specie
of Unio occur in considerable abundance in a shale

containing plants of the carboniferous period, and over-

* Vol. I. pp.201, to 203.

+ Vol. I. p. 158.

\ Hibbert, Trans. R. S. Edinb. vol. xiii., and L. Horner,
Edinb. New Phil. Journ. April 1836.

Ch. XXIII.3

OLD RED SANDSTONE.

295

been

lying a bed of coal. The coal has
from beneath the shells, which have been already
proved to extend over an area five thousand feet
square. The shelly stratum is about eighteen inches
thick ; and the animals have evidently died at various
ages, the shells being of every size. This accumu-
lation of bivalves of one species, and of this form,
seems clearly to indicate the continuance on the spot
of a body of fresh water, such as might be found in

the estuary of a river.*

In the Shropshire coal-field near Bridgnorth, and in
other places, Mr. Murchison has shown that the upper
coal-measures contain a subordinate bed of limestone,
which he has termed lacustrine, as a small species of
shell, supposed to be a Planorbis, is plentifully im-

bedded in it.f

The fossils of the mountain limestone, above al-
luded to, are marine, and contain, among other genera
of shells not discovered in newer deposits, the Ortho-
cera (see Fig. 211.), a chambered univalve, sometimes
many feet in length.

Fig. 211.

Fig. 212.

Orthoceras laterals 9 Phillips.
Mountain limestone. .

0. giganteum, Sow"
Section shewing the siphuncle

, Old Red Sandstone. N., Table I., p. 306.

Beneath the coal-series in the northern part of
Fifeshire in Scotland, and the southern half of Forfar-

* Fossil Flora, by Lindley and Hutton, No. 10.
f Proceedings of Geol. Soc, No. 38. p. 119.

O 4

296

OLD RED SANDSTONE.

[Book IV.

shire, a formation occurs of great thickness, composed
of red marl, conglomerate, red and white sandstone,
and shales of various colours, for the most part devoid

In some of the shales, however,

of organic remains.

impressions of plants, apparently marine, have been
met with; and in the flaggy sandstones containing a
slight admixture of carbonate of lime, the scales and
other remains of fish are not unfrequent. They belong
to a genus named by Dr. Agassiz « Cephalaspis," or
" buckler-headed," from the extraordinary shield which
covers the head. (See Fig. 213.) This peculiar form

Fig. 213.

Cephalaspis Lyellii, Agass. Length 6f inches.

This figure is from a specimen now in my collection, which I procured
at Glammis in Forfarshire. The species, which Br. Agassi* has
named after me, will be described in his work on Fossil Fish.

of fish, which is quite unknown in the coal-strata,
seems characteristic of the old red sandstone generally;
for it is found in Herefordshire and other counties of
England and Wales, where the old red sandstone is
largely developed. All the animal and vegetable
remains hitherto discovered in this series are dis-

tinct from those of the overlying coal, or subjacent

transition strata.

Ch, XXIII.]

TRANSITION FORMATIONS,

297

9. Transition, or Greywacke Formations. O. & P.,

Table L, p. 306.

Continental and English authors have not always
been agreed where the line of separation sl\ould be
drawn between the secondary and transition form-
ations. Some of them, for example, have included the
carboniferous group in the secondary, others in the
transition system. But in England the old red sand-
stone has been generally considered as the lowest
member of the secondary series.

The name of transition was first given by Werner to
certain sedimentary deposits consisting, in the Hartz
and many parts of Germany, of arenaceous and brec-
ciated rocks which alternate with argillaceous schist,
and are sometimes associated with coralline and shelly
limestones. These were supposed to have been the
earliest formed strata when the ocean first became
habitable by aquatic beings. Although the principal
Members of this group, where it is largely developed,
are evidently of mechanical origin, they often alter-
nate with beds of quartz and argillaceous schist, not
distinguishable mineralogically from crystalline rocks

is primitive. Hence, as was before
stated, the term transition was adopted to express the
theory that, at this period, the causes which had given
r i$e to crystalline formations were still in action ; while
those which produced stratified sedimentary rocks,
deluding organic remains, were also beginning to

°perate.

The characteristic group called in German " Grau-

w acke," an old miner's term, is an aggregate of small

■

Werner

(

stone)

a &d argillaceous schist, cemented together by argil-

o 5

■

■ . ■

a fr

298

TRANSITION FORMATIONS.

[Book IV.

laceous matter. But far too much importance has
been attached to this kind of rock, as if it were p e-
culiar to a certain epoch in the earth's history, whereas
it is only an accidental variety of argillaceous sand*
stone, probably in some cases altered by heat. There
are parts of England and Sweden where fossiliferous
strata more ancient than the old red sandstone a fe
largely developed, and yet where no rocks answering
mineralogically to the Grey wacke of the Germans # re

discoverable.

The first great step towards a general table of super*
position of the British fossiliferous groups below the
old red sandstone, each distinguished by certain m 1 "
neral characters and organic remains, has recently
been made by Mr. Murchison, and his arrangement
has been adopted in Table I., p. 306.

Mr. Murchison has had an opportunity of tracing
the succession of deposits in a regular descending
series, from the old red sandstone with which they a re
in part covered, to the subjacent and unconformable
greywacke rocks of South Wales. As far as his &'
amination has hitherto proceeded, all the species °*
zoophytes and shells differ from those of the carbon 1 *
ferous limestone ; while the fossils of his four great
subdivisions are distinct from each other.*

He has proposed the term " Silurian," as a general
name for this whole system of rocks, derived fro** 1
" Silures," the principal tribe of Celts or ancient B ri "
tons, who occupied part of Wales and the bordering
counties of England, where these ancient fossil ifero^s
strata are most distinctly exhibited. The Ludlo^
rocks and the Wenlock limestone may he classed & s
the Upper Silurian group, being the deposits whic* 1

* Proceedings of Geol. Soc. London, No. 34. 1834.

■■

MB^^mm

Ch. XXIII.]

TRANSITION FORMATIONS.

299

are immediately below the old red sandstone ; while

Caradoc

Lower Silurian group. Below all these there are othe r

Wales

to the Silurian strata.

Among the fossils of the Silurian formations, zoo-
phytes and crinoidea are the most numerous ; and some
of the limestones, which are in great part composed of
them, agree in their general character with those now
b progress in seas where stone-corals are abundant.

>ite (see

Fig. 214.

Fig. 215.

Calymene Blwmenbachii, Asaphus Buchii.

^rongniart, PI. 1. fig- 1. commonly called Brongniart, PI. 2. fig. 2.. A.

" Dudley trilobite " Lower Silurian.

Upper Silurian rocks.

taceous animal, of which no species is known in form*
ations newer than the mountain limestone, is also
characteristic of the rocks of this period; so also the
Orthocera, a chambered univalve, found also in the
carboniferous limestone (see Fig. 211. p. 295.), but
hitherto in no newer deposit. On the other hand,
some of the shells belong to recent genera, as the
Terebratula, of which there is a great variety. The
only vertebrated remains hitherto found are a few
bones of fishes. The shells and zoophytes of these

■

formations have been studied in Germany by Count
Munster, Professor Goldfuss, and M. Steininger. In
Nassau, M. Stift has endeavoured to classify the dif-
ferent subdivisions of the same series chiefly by refer-
ence to their mineralogical characters.

o 6

300

TRANSITION FORMATIONS.

[Book IV.

also, who has recently published a geological map of
the south of Sweden, as well as Professor Wahlenberg
and the late M. Dalman, have described and figured
many fossil productions from these strata in Sweden.

With this " Silurian " group I shall conclude ; for it
does not appear that any antecedent periods can yet
be established on the evidence of a distinct assemblage
of fossil remains. Traces of organization do undoubt-
edly occur in rocks of still higher antiquity, for some
of which Professor Sedgwick has proposed the name
of " Cambrian ; " but they can scarcely be referred to
a distinct geological period, until we have obtained
more data for determining the specific characters of #
considerable number of fossils.

The annexed table will explain the order of super-
position of the successive groups of fossiliferous strata
hitherto established in Europe ; it should be remem-
bered, however, that it is in a small part of western
Europe only that almost all this series of monuments

has been discovered.

301

TABLE I.

ring the Order of Superposition, or Chronological Suc-
Ce ssion, of the principal European Groups of Sedimentary
at *d Fossiliferous Strata.

This Table is also referred to in the Glossary.

Names of the principal Members and Mineral
Nature of the Formation, in Countries where it
has been most studied.

Some of the Localities

where the Form-
ation occurs.

The deposits of this period are for the most part concealed under

existing lakes and seas.

Consolidated sandy and gravelly beds (a),
travertin limestones (b), calcareous sand-
stones with broken shells (c), coral lime-
stone, consisting of corals, shells, &c. (d),
compact limestone (e).

a. Delta of the

Rhone.
6. Tivoli, and other
parts of Italy.

c. Shore of Island
of Guadaloupe.

d. Coral reefs in
Pacific, &c.

e. Bermudas.

Marine.
Limestone, sands,
clays, sandstones,
conglomerates, marls,
with gypsum ; con-
taining marine fos-
sils (a).

Freshwater.
Sands, clays, sand-
stones, lignites, &c. ;
containing land and
freshwater fossils (b).

a. Sicily, Ischia.

b. Colle in Tus

cany

Subapennine marly
Subapennine yellow
sand, English "crag,"
and other deposits,
as in B., containing
marine fossils (a).

Similar deposits to
B. ; containing land
and freshwater fos-
sils (6).

Faluns of the Loire,
and other deposits
varying in mineral
composition, as those
in B. and C, con-
taining marine fos-
sils (a).

Similar deposits to
B. and C. ; contain-
ing land and fresh-
water fossils (6).

a Subapennine
formations, Per-

Nice,
and

pignan,

Norfolk,

Suffolk.

b. Near Sienna, &c.

a. Touraine, Bor-
deaux, Valley of
Bormida, Super-
ga near Turin,
Basin of Vienna.

b. Saucats, twelve
miles south of
Bordeaux.

' I

;

302

Periods

and
Groups.

•

W *3

cu §

•

fc I

z .§

5 s

§ 8

•

*rH

n
o

S* o

TABULAR VIEW

TABLE I.

continued.

Names of the principal Members and Mineral
Nature of the Formation, in Countries where
it has been most studied.

SomeoftheLoca j,.,

where the
ation occurs.

Calcaire grossier
(a), London clay,
sands, sandstones,
&c, with marine
fossils (b).

Calcaire siliceux —
sandstones and con-
glomerates, red marl,

and white
limestone,
I marl

green

marls

gypseous

with land and fresh-

water fossils (c).

a. ■ Paris basin-

b. Paris, I/>*S

and Hanip^f

basins, l sle
Wight. < s ]e

c. Paris basin, >

vergne,
Cantal.

1. Maestricht Beds. — Soft
yellowish- white limestone with
siliceous masses, resembling
chalk (marine).

2. Chalk withjlints (marine).

St. Peter's Mount
tricht.
Ciply, near Mons.

3. Chalk without flints (ma-
rine).

Upper green sand (ma-
rine). — Marly stone, and sand
with green particles ; layers of
calcareous sandstone.

5. Gault (marine). — Blue
clay, with numerous fossils,
passing into calcareous marl
in the lower parts.

6. Lower green sand (ma-
rine). — Grey, yellowish, and
greenish sands, ferruginous
sands and sandstones, clays,

cherts, and siliceous lime-
stones.

North and South V ^
and parts of the in ter r e y,
ing Weald of Kent, S*

and Sussex. ~uv

Yorkshire; North ot

land.

Beauvais, France-

1. Weald Clay (freshwater).
— Clay for the most part with-
out intermixture of calcareous
matter, sometimes including
thin beds of sand and shelly

limestone.

1 , 2. Extensively deV

II"

*°* and

•i

6 1

2 s

• *■<

o
O

OF FOSSILIFEROUS STRATA.

303

TABLE L — continued.

Names of the principal Members and
Mineral Nature of the Formation,
in Countries where it has been most

studied.

Some of the Localities where the

Formation occurs.

2. Hastings sands (fresh*
water). — Grey, yellow, and
reddish-brown sands, sand-
stones, clays, calcareous grits
passing into limestone.

loped in the central parts of
)*Kent, Surrey, and Sussex.
3. Isle of Purbeck, in
Dorsetshire.

3. Purbeck beds (freshwater).
Various kinds of limestones
and marls.

] . Portland beds (marine).
Coarse shelly limestone, fine-
grained white limestone, com-
pact limestone — all more or
less of an oolitic structure;
beds of cherts.

2. Kimmeridge clay (marine).
Blue and greyish-yellow
slaty clay, containing gypsum,
bituminous slate (Kimmeridge
coal).

Isle of Portland, Tisbury
in Wiltshire, Aylesbury.

Cal-

Near Kimmeridge on
coast of Dorsetshire — Sun-
ning Well, near Oxford.

3. Coral rag( marine). -
careous shelly freestones,
largely oolitic; coarse lime-
stone, full of corals; yellow
sands ; calcareous siliceous
grits.

4. Oxford clay (marine). ^
Dark blue tenacious clay, with

bituminous shale,

septaria, I

sandy limestone

rock), iron pyrites, gypsum

Headington, near Oxford
Farringdon, in Berkshire
Calne and Steeple Ash-
ton, in Wiltshire — Somer-
setshire.

■-■

(Kelloway

New Malton, in Yorkshire
Lincolnshire — Cam-
bridgeshire — Huntingdon-
shire, and midland counties

— abundantly near Oxford

— Somersetshire — Dorset-
shire.

5. Cornbrash

(marine).
Grey or bluish rubbly lime-
stone, separated by layers of
clay. i

Malmsbury, Atford,Wrax
all, Chippenham.

304

TABULAR VIEW

TABLE I. — continued.

Periods and
Groups.

Q
O

<
Q

Names of the principal Members and
Mineral Nature of the Formation,
in Countries where it has been most
studied.

Some of the Localities where

Formation occurs.

6. Forest marble (marine).
Calcareo-siliceous sand and
gritstone; thin fissile beds of
limestone, with clay partings;
coarse shelly limestone.

Whichwood Forest,
fordshire — Frome, s0
east of Bath.

a.
o

c
o

7. Great oolite (marine).
White and yellow oolitic cal-
careous freestone, coarse shelly
limestone, layers of clay.

Oolitic limestone, with re-
mains of land animals, birds,
amphibia, plants, sea-shells(a).

Bath— BurfordinOsf<>

shire— Bradfordin Wil^
a. Stonesfi eld, near W°

stock, Oxfordshire.

•P-N

►J

8. Fuller's earth clay (ma-
rine). — Clay containing
some places fuller's earth.

Near Bath

9. Inferior oolite (marine).
Soft freestone, sand with cal-
careous concretions.

Cotteswold Hills
dry Hill, near Bristol

Limestones of various qualities, clays, sands, and
stone, containing the same fossils as those occurring
series of the oolitic group of England, constitute the
body of the Jura chain of mountains, and cover vast

of country in Germany.

tit

Lias (marine). — Shale and
sandy marl stone.

Blue, white, and yellow
earthy limestone, usually in
thin beds, interstratified with
clay, often slaty and bitumin-
ous*

Lyme Regis in ^° l

shire, and in many p af , j r e

Somersetshire — Yo** s ^e
— in Sutherlandshire?

Hebrides, and North ot
land. i { o

In France, as at Metz* a**
a considerable extent i n ^
many, as in the Swabian J

1. Xeuper, or variegatedmarls. Neighbourhood of *° %p

— Red, grey, green, blue, and mountains, and many P t- .

white marls, sandstones, con- of Wurtemberg and ™

glomerates,and shells, contain- phaiia, Nuremberg,
ing gypsum and rock-salt.

•<

S
*

■

OF FOSSILIFEROUS STRATA.

305

TABLE I. — continued.

Names of the principal Members and
Mineral Nature of the Formation,
in Countries where it has been most

studied.

2. Muschelkalk (marine).
Grey, blue, and blackish lime-
stone, with alternating clay and
marl, and with siliceous layers,
and nodules.

3. Variegated (Bunter) sand-
stone. — Red, white, blue, and
green siliceo-argillaceous sand-
stone, often micaceous and con-
taining gypsum and rock-salt.

1. Magnesian limestone {a)
(marine). — Marl-slate, shelly
limestone, variegated marls,
yellow magnesian limestone.

Zechstein of Germany (b)
limestone — marl-slate, con-
taining copper ore, and im-
pressions of fish.

2. Red conglomerate.
stones, conglomerates;
and marls.

Sand-
sands,

1 . Coal
water and

(fresh-
San d-

measures
^^ ^^ marine). ^^^^^^
stones, grits, conglomerates,
clays, with ironstone, shales,
and limestone, inter stratified

with beds of coal.

2. Mountain limestone (ma-
rine). — Grey, compact, and
crystalline limestone, abound-
ing in lead ore in North of
England, and alternating with
coal measures in Scotland.

Some of the Localities where the

Formation occurs.

Extensively developed in
Germany and France.

Hitherto no beds in Eng-
land have been identified with
the formation.

Nottinghamshire

shire.
Stuttgardt.

York-

a. Nottinghamshire, Derby-
shire, Yorkshire, Durham,
Northumberland.

b. Mansfeld in Thuringia.

Neighbourhood of Exeter

Northumberland, Durham,
Yorkshire, Lancashire, Staf-
fordshire, Somersetshire ,
South Wales, Valleys of the
Forth and Clyde.

District of Liege, West-
phalia, Silesia, Bohemia, &c.

Mendip Hills, Derbyshire,
Yorkshire, Durham, North-
umberland, Lanarkshire,
Linlithgowshire, many parts

of Ireland.

North-west of Germany,
Belgium, North of France.

306

TABULAR VIEW OF STRATA.

TABLE I. — continued.

Periods and
Groups.

</2

Names of the principal Members and

Mineral Nature of the Formation,

m Countries where it has been most
studied.

•

-o

S-<

Some of the Localities wb^

Formation occurs.

t&<

1. Old red sandstone — Coarse
and fine siliceous sandstones
and conglomerates of various
colours, red predominating.

Extensively develop^,

Shropshire and H e <j u fli'
shire, Brecknockshire*

fries-shire, Forfarshire

Silesia, Bohemia.

I. Ludlow rocks (marine). —
Argillaceous limestone, sandy
shale.

2. Wenlock limestone (ma-
rine). — Coralline limestone
and argillaceous shale, with
nodules of earthy limestone.

Ludlow Castle, ShroP
Aymestry and ^
Herefordshire.

vfcy

Wenlock Edge, Sh^P s
Dudley, Worcester^ '

3 . Caradoc sandstones ( m ar i ne ) .
— Shelly limestone and mica-
ceous sandstone, quartzose
grits, and sandy limestones.

Horderly, Shropsb 1 ^.
May Hill, Gloucester? /

East flank of W^L

Caer Caradoc, Shrop s11

4. Llandeilo flags (marine).
— Calcareous flags, sandstone
and schist.

• Llandrindod, near ^: p

Radnorshire. ^ W

Caermarthenshire.

Fossiliferous greywacke, and rocks older than ^ e - c &
rian, but in which no distinct assemblage of orgP^^ff
mains have as yet been specifically determined. V* $P
Sedgwick has proposed the name of " Cambrian" iot
formations.

^^mm

^■M^BM^

307

"v.

CHAPTER XXIV.

A ^LOGY OF THE OLDER FOSSILIFEROUS TO THE

TERTIARY

STRATA.

Secondary fresh-

at land as well as sea existed at each successive period
former continents placed where it is now sea
^ater deposits, why rare (p. 313.)— Persistency of mineral com-
Position, why apparently greatest in older rocks — Supposed uni-
Ve rsality of red marl formations — Secondary rocks, why more

Co &solidated why more fractured and disturbed (p. 318.)

^condary volcanic rocks of many different ages.

* the last chapter I stated that no detailed account of
!^ e older fossiliferous formations would be attempted
iri this work, and that I should confine myself almost
e5c clu s i ve iy to the inquiry how far the rules of inter-
station previously adopted for the tertiary groups
^ght be applied to the phenomena of more ancient
str ata. 'To this point the following remarks are chiefly

ected :

tffi

The existence of

a **d as well as sea, at every geological period, is
^tested by the remains of terrestrial plants imbedded
ln the deposits of all ages, even the most remote. We

^ fluviatile shells not unfrequently in the secondary
St * at a, and here and there some freshwater form-
ations; but the latter are less common than in the
j^tiary series. For this fact the reader's mind has

eeri prepared, by the views advanced in the third

:•

308

SECONDARY FORMATIONS.

[Book

IV.

chapter respecting the different circumstances unde
which the secondary and tertiary strata appear to ha*
originated. The secondary, it was suggested, &*$
have been accumulated in an ocean like the Pac^
where coralline and shelly limestones are forming 5 ° r
in a basin like the bed of the western Atlantic, ^ l ° l
may have received, for ages, the turbid waters of g rea
rivers, such as the Amazon and Orinoco, each dra* n '

ing a considerable extent of continent. The

te rtiaf!/

deposits, on the other hand, very probably accumula te
during the growth of a continent, by successive e^ e
gence of new lands, and the uniting together of isla n ° '
During such changes, inland seas and lakes would
caused, and their basins afterwards filled up with $ e
ment, and then raised above the level of the waters*

That the greater part of the space now occupied J
the European continent was sea when some of *
secondary rocks were produced, must be inferred f r °

the wide areas over which several of the marine g r ° u P
are diffused ; but we need not suppose that the q uar
tity of land was less in those remote ages, but rae re *
that its position was very different.

It has been shown that, immediately below the ch&
and green-sand, a fluviatile formation, called the W^'
den, occurs, which has been ascertained to extend fr°
west to east about 200 English miles, and from n° r _J

west to south-east about 220 miles, the depth or V&
thickness of the beds, where greatest, being

abo

2000 feet. *

that

These phenomena clearly indicate
there was a constant supply in that region, for a 1°*™
period, of a considerable body of fresh water, such a
might be supposed to have drained a continent, o r

Fitton's Geology of Hastings, p. 58.

XXIV.]

POSITION OF FORMER CONTINENTS.

309

ar ge island, containing within it a lofty chain of moun-
ts. Dr. Fitton, in speaking of these appearances,
^Us to our recollection that the delta of the newly
^covered Quorra, or Niger, in Africa, stretches into

e interior for more than 170 miles, and occupies,
lt * s supposed, a space of more than 300 miles along
tl)e coast ; thus forming a surface of more than 25,000
^ u are miles, or equal to about one half of England. *

fr asked where the continent was placed from the
^ins of which the Wealden strata were derived, we
^§ht be almost tempted to speculate on the former
* xi stence of the Atlantis of Plato as true in geology,
though fabulous as an historical event. We know
^ at the present European lands have come into exist-
eftc 'e almost entirely since the deposition of the chalk

(se e

map

)

u *ficed for the disappearance of a continent of equal

^ a §mtude, situated farther to the west.

^ut among the numerous fossils of the ancient delta

the Wealden no remains of mammalia have been

et ected ; whereas we should naturally expect, on

Staining the deposits recently formed at the mouths

0f the Quorra, Indus, or Ganges, to find, not only the

^es of birds and of amphibious and land reptiles, but
s ° those of the hippopotamus, and other mammalia
^ich frequent the banks of rivers.

Mr. Mantell

a ^als and plants found fossil in the Wealden havi

^ It: h the exception of the testacea and other aquatic

ri ^ e s, been transported for a considerable distance,

)e stems of the plants being, for the most part, torn

Fitton, Geol. of Hastings, p. 58 , who cites Lander's Travels.

t Geol. of S. E. of England, p. 232.

■

S10

SECONDARY FORMATIONS.

•

[Book

iv.

and intermingled with pebbles of quartz, slate, a n
jasper; while the bones of lizards, turtles, and fish,^'
detached from the skeleton, and more or less brok en
and rolled. But, admitting that these fossils * ere
drifted for many a league, we might fairly expect that*
at least, some fragments of mammiferous bones ^ ol}
have reached the delta.

It is certainly a startling proposition to suppose

that

a continent covered with vegetation, which had jts
forests of palms and tree-ferns, and its plants allied t0
the Dracaena and Cycas, which was inhabited by W$ e
saurians, and by birds, was, nevertheless, entire 1 '
devoid of land quadrupeds. If the proofs were c Qti '
fined to the Wealden, we might hesitate to lay m uC
stress on mere negative evidence, since extensive °*'
posits of the Eocene period, such as the London cM'

flu*

have as yet yielded no mammiferous fossils,
when we find the same general absence of marnm

in strata of the Oolitic and Liassic eras, we can har<^
refuse to admit that the highest order of quadrup
was very feebly represented in those ages, when
small Didelphys of Stonesfield was entombed. &>**
of the bones, indeed, collected by Dr. Buckland fr 00
the oolitic series, have been pronounced by Cuvier t0
be cetaceous; but that naturalist has himself remark
how closely the vertebras of the larger reptiles re '
semble those of certain dolphins; so that it is h»g b ^
desirable that the fossils alluded to should be re '
examined with great care. *

So far, then, as our present inquiries enable " s
judge, there are strong indications that, during the

■

* Mantell, Geol. of S. E. of England, p. 282. ; and see
Vol. I. p. 232.

rfoo

. L

V >

■•.

■#.

■MiBMII

XXIV.]

ABSENCE OF MAMMALIA.

• /

311

Periods

Pen

Wealden

there

a large development of the reptilia, at the ex-
s e> as it were, both of the cetaceous and terrestrial

^nialia.

^ may be well, then, to inquire whether this differ-
Ce in the state of animal life in the northern hemi-
j*ere, at these remote periods, is irreconcileable with
e Motion of the constancy and uniformity of the laws
^ch govern the changes of the organic world. Would
e almost entire suppression of one important class of
er tebrated animals, and the larger development of
pother, if fully established on farther investigation,
l Vy that there are no fixed rules according to which
^ e form, structure, and attributes of animals are
aCc ommodated to the endless vicissitudes of the earth's
^face ? Or are the rules, if any, made to endure for
time only, new ones being substituted at each suc-
e $si Ve period ? Or, is it conceivable that the distinct
°°logical characters of certain secondary groups, as
spared to others of the tertiary epoch, may depend
11 Ws as uniform as those which, from one century
Mother, appear to determine the growth of certain
.^es of plants and animals in the arctic, and of others

ltl tropical ""-*

regions

^ Australia, New Zealand, and many other parts of

e southern hemisphere, where the indigenous land

^drupeds are comparatively few and of small dimen-

*° n s, the reptiles do not predominate in number or size.

. e deposits formed at the mouth of an Australian

IVer 5 within the tropics, might contain the bones of

*% a few small marsupial animals, which, like those

0f Stonesfield, might hereafter be discovered with diffi-

? ll y by geologists ; but there would, at the same

lrne > be no megalosauri and other fossil remains, show-

■

I ■

ill

312

SECONDARY FORMATIONS

[Book

*#■

ing that large saurians were plentiful on the land an
in the waters when mammalia were scarce.

No precise analogy, therefore, can here be fr un
to the state of the animal kingdom supposed to h* v
prevailed during the secondary periods when a h$
temperature pervaded European latitudes. But it AW
be useful to consider whether any of the anomalies n°

caused by climate in the relative number and l
portance of different classes of the vertebrata may 11
in some degree illustrate this topic. In the Arctic
gions, for example, reptiles are small, and somettf* 1
wholly wanting, where birds, large land quadrup e
and cetacea abound. We meet with bears, wol v

foxes, musk oxen, and deer, walrusses, seals, w

hal<*

and narwals, in regions of ice and snow, where

the

smallest snakes, efts, and frogs are rarely if eV

seen.

On what grand laws in the animal physiology

th*

remarkable phenomenon depends, cannot, in the p r
sent state of science, be explained; nor could we p r
diet whether any opposite condition of the atmosph e
in respect to heat, moisture, and other circumstafl c J
would bring about a state of animal life which & l o
be called the converse of that above described ; a st*
of things in. which large mammalia might abound? a

reptiles disappear. We ought, however, to rec

oil**

$
a

that a mean annual temperature like that now e> .
perienced at the equator, co-existing with the uneq u **
days and nights of European latitudes, and with
distinct distribution of sea and land, would imply ^
climate to which we have now no parallel. ^°
sequently, the type of animal and vegetable existed
required for such a climate might deviate as wi<* e J
from that now established in any part of the globe?

^«a

^.XXIV.] PERSISTENCY OF MINERAL CHARACTER. 313

■do the Flora and Fauna of our tropical differ from
*hose of our arctic regions.

Secondary freshwater deposits, why rare. — If there
w ere extensive tracts of land in the secondary period,
^e may presume that there were lakes also ; yet I am
n ot aware of any pure lacustrine formations inter-
s tratified with rocks older than the chalk. Perhaps
their general absence may be accounted for by the
^doption of the theoretical views above set forth ; for
** the present ocean coincides for the most part with
the site of the ancient continent, the places occupied
ty lakes must have been submerged. It should also
he recollected, that the area covered by lakes, at any
°**e time, is very insignificant in proportion to the
°cean ; and, therefore, we may expect that, after the
garth's surface has undergone considerable revolutions
111 its physical geography, the lacustrine strata will be
c °ftcealed, for the most part, under superimposed ma-
* ll *e deposits.

Persistency of mineral character. — In the same man-
ne r as it is rare and difficult to find ancient lacustrine
str ata, so also we can scarcely expect to discover newer
Marine groups preserving the same lithological charac-
ter s continuously throughout wide areas. The chalk
**°w seen stretching for thousands of miles over difFer-
er *t parts of Europe has become visible to us by the
Effect, not of one, but of many distinct series of move-

ment

s. Time has been required, and a succession of

geological periods, to raise it above the waves in so
**any regions ; and if calcareous rocks of the Eocene
r Miocene periods have been formed, preserving a
°mogeneous mineral composition throughout equally
^tensive regions, it may require convulsions as nume-
1 as all those which have occurred since the origin

*ou

vol. iv.

■

314?

SECONDARY FORMATIONS.

[Book

IV.

of the chalk to tying them up within the sphere o
human observation. Hence the rocks of more modern
periods may appear of partial extent, as compared
those of remoter eras, not because there was any
original difference of circumstances throughout the
globe when they were formed, but because there h^
not been sufficient time for the development of a gr<*
series of subterranean volcanic operations since tbe»

origin. t

At the same time, the reader should be warned n
to place implicit , reliance on the alleged persistent
of the same mineral characters in secondary rocK^
When it was first ascertained that an order of s tf ^
cession' could be traced in the principal groups ^
strata above enumerated, names were given to ea<y
derived from the mineral composition of the rocks ^
those parts of Germany, England, or France, wh e ^
they happened to be first studied. When it was a# e ^
wards acknowledged that the zoological and pbfi
logical characters of the same formations were far &°
persistent than their mineral peculiarities, the o ^
names were still retained, instead of being exchaog^
for others founded on more constant and esseI \ at
characters. The student was given to understand * ^
the terms chalk, green-sand, oolite, red marl, coal, *^
others, were to be taken in a liberal and exten ^
sense ; that chalk was not always a cretaceous & ' e
but in some places, as on the northern flanks o ■
Pyrenees, and in Catalonia, a saliferous red m
Green-sand, it was said, was rarely green, and ^
quentlynot arenaceous, but represented in V 9 *® &
the south of Europe by a hard dolomitic limeSt t ° ure
In like manner, it was declared that the oolitic teS

* See some remarks on this subject, Vol. I. P- ] 3

Ch -XXlV.] PERSISTENCY OF MINERAL CHARACTER. 315

^as rather an exception to the general rule in rocks of
the oolitic period, and that no particle of carbonaceous
Matter could often be detected in the true coal form-
ation of many districts where it attains great thickness,
^t must be obvious to every one, that inconvenience
and erroneous prepossessions could hardly fail to arise
* r om such a nomenclature ; and accordingly a fallacious
**iode of reasoning has been widely propagated, chiefly
by the influence of a language so singularly inappro-
priate.

After the admission that the identity or discordance
°f mineral character was by no means a sure test of
agreement or disagreement in the age of rocks, it was
s tiU thought, by many geologists, that if they found
a rock at the antipodes agreeing precisely in mineral
composition with another well known in Europe, they
could fairly presume that both are of the same age,

u Mil the contrary could be shown.

Now, it is usually difficult or impossible to combat
Sl *ch an assumption on geological grounds, so long as
^e are imperfectly acquainted with the geology of a

distant

country, inasmuch as there are often no or-

ganic remains in the foreign stratum; and even if
*hese abound, and are specifically different from the
*°ssils of the supposed European equivalent, it may be
Ejected that we cannot expect the same species to
have inhabited very distant quarters of the globe at
^e same time.

Supposed universality of red marl. — I shall select a
% e *narkable example of the erroneous mode of general-
l2:in g now alluded to. A group of red marl and sand-
f to ne, sometimes containing salt and gypsum, is found
n England interposed between the lias and the car-

oniferous strata. For this reason, other red marls

p 2

;

316

SECONDARY FORMATIONS.

• [BooklV-

and sandstones, associated some of them with salt, an
others with gypsum, and occurring not only in differen
parts of Europe, but in Peru, India, the salt deserts o
Asia, those of Africa, in a word, in every quarter o
the globe, have been referred to one and the same
period. The burden of proof is not supposed to res^
with those who insist on the identity of age of a
these groups ; so that it is in vain to urge as an
jection the improbability of the hypothesis whit*
would imply that all the moving waters on the g^ e
were once simultaneously charged with sediment °

a red colour. k

The absurdity of pretending to identify, in age
the red sandstones and marls in question, has at leng*
been sufficiently exposed, by the discovery that, eve»
in Europe, they belong decidedly to many differe^

epoct

sandstone and red marl, with which the rock-salt °

Cardona is associated, may be referred to the period

our chalk and green-sand. I was led to this opin' 00

when I visited Cardona in 1830, and before I was a^ a

is.

clu'

sions.

I have pointed out that in Auvergne there **

red marls and variegated sandstones, which are und 1 ^
tinguishable in mineral composition from the new r
sandstone of English geologists, yet which were dep

sited in the Eocene period : and, lastly, the gyP se ° h
red marl of Aix, in Provence, formerly supposed to
a marine secondary group, is now acknowledged to
a tertiary freshwater formation. *

Secondary

One

a*ti

the points where the analogy between the secon
and tertiary formations has been supposed to fail? xs

* Ann. des Sci. Nat., Avril, 1831, p. 449.

°h. XXIV. ]

CONSOLIDATION.

317

greater degree of solidity observable in the secondary-
series. Undoubtedly the older rocks, in general, are
*fiore stony than the newer; and most of the tertiary
s trata are more loose and incoherent in their texture

than the secondary. Many exceptions, however, may
be pointed out, especially in those calcareous and sili-
ceous deposits which have been precipitated in great
part from the waters of mineral springs, and have been
originally compact. Of this description are a large
proportion of the Parisian Eocene rocks, which are more
stony than most of the English secondary groups.

But strata in general have evidently been consoli-
dated subsequently to their deposition by a slow lapidi-
fying process. Thus loose sand and gravel are bound
together by waters holding carbonate and oxide of
iron, carbonate of lime, silica, and other ingredients in
solution. These waters percolate slowly the earth's
crust in different regions, and often remove gradually
the component elements of fossil organic bodies, sub-
stituting other substances in their place. It seems,
Moreover, that the draining off of the waters during
the elevation of land may often cause the setting of
particular mixtures, in the same manner as mortar
hardens when desiccated, or as the recent soft marl of
Lake Superior becomes highly indurated when ex-
posed to the air.* The conversion of clay into shale,
a nd of sand into sandstone, may, in many cases, be
attributed to simple pressure, produced by the weight
°f superincumbent strata, or by the upward heaving of
subjacent masses during earthquakes. Heat is another
c ause of a more compact and crystalline texture, which
^ill be considered when I speak of the strata termed

" primary." All the changes produced by these various

* Vol. I. p. 344. -

p 3

318

SECONDARY FORMATIONS.

[Book

IV.

x -

means require time for their completion ; and this may
explain, in a satisfactory manner, why the older rocks
are most consolidated, without entitling us to resort to
any hypothesis respecting an original distinctness in
the degree of lapidification of the secondary strata.

Secondary, why more disturbed.— As the older form-
ations are generally more stony, so also they are more
fractured, curved, elevated, and displaced, than the
newer. Are we, then, to infer, with some geologists?
that the disturbing forces were more energetic in re-
moter ages? No conclusion can be more unsound;
for as the moving power acts from below, the newer
strata cannot be deranged without the subjacent rocks
participating in the movement ; while we have evidence
that the older have been frequently shattered, raised?
and depressed, again and again, before the newer rocks
were formed. It is evident that if the disturbing

power of the subterranean causes be exerted with

uniform intensity in each succeeding period, the quan-
tity of convulsion undergone by different groups oi
strata will generally be great in proportion to their
antiquity. But exceptions will occur, owing to the
partial operation of the volcanic forces at particular
periods; so that we sometimes find tertiary strata
more elevated and disturbed, in particular countries*
than the secondary rocks in others.

Some of the enormous faults and complicated dis-
locations of the ancient strata may probably have
arisen from the continued repetition of earthquakes in
the same place, and sometimes from two distinct
series of convulsions, which have forced the same
masses in different, and even opposite, directions i
sometimes by vertical, at others by horizontal, move-
ments.

c h. XXIV.]

VOLCANIC ROCKS.

319

yf different

The

association of volcanic rocks with different secondary
strata is such as to prove that there were igneous
eruptions at many distinct periods, as also that they
^ere confined during each epoch, as now, to limited
areas. Thus, for example, igneous rocks contempora-
neous with the carboniferous strata abound in some
countries, but are wanting in others. So it is evident
that the bottom of the sea, on which the oolite and its
contemporary deposits were thrown down, was, for the
toost part, free from submarine eruptions ; but at some
Points, as in the Hebrides, it seems that the same
ocean was the theatre of volcanic action. It was before
remarked*, that, as the ancient eruptions occurred
in succession, sufficient time usually intervening be-
tween them to allow of the accumulation of many
subaqueous strata, so also should we infer that sub-
terranean movements, which are another portion of
the volcanic phenomena, occurred separately and in
succession.

* Book i. chap* v.

P 4

- ;

320

CHAPTER XXV.

RELATIVE ANTIQUITY OF MOUNTAIN-CHAINS.

Theory of M. Elie de Beaumont — His opinions controverted
His method of proving that different chains were raised at dis-
tinct periods, and that the rise of others was contemporaneous,
not conclusive — His doctrine of the parallelism of contem-
poraneous lines of elevation _ Objections (p. 326.) —Howfa r
anticlinal lines formed at the same period are parallel -*
Difficulties in the way of determining the relative age of
mountains.

That the different parts of our continents have been
elevated, in succession, to their present height above
the level of the sea, is an opinion which has been gr**'
dually gaining ground with the progress of science 5
but no one before M. Elie de Beaumont had the merit

t ^

even of attempting to collect together the recorded
facts which bear on this subject, and to reduce then 1
to one systematic whole. The above-mentioned geo-
logist was eminently qualified for the task, as one wb°
had laboured industriously in the field of original ob-
servation, and who combined an extensive knowledge
of facts with an ardent love of generalization.

But, as I cannot admit the accuracy of an import'
ant part of his method of reasoning on this topic, and
as his principal conclusions appear to me very uncer-
tain, I must explain the reasons of my dissent, having
first given a brief summary of the most prominent fea-
tures of his theory.

■

°b. XXV.]

ANTIQUITY OF MOUNTAIN-CHAINS.

321

1st. M. de Beaumont supposes, " that in the history
°f the earth there have been long periods of compara-
tive repose, during which the deposition of sedimentary
Matter has gone on in regular continuity ; and there
have also been short periods of paroxysmal violence,
during which that continuity was broken.

" 2dly. At each of these periods of violence or
^evolution' in the state of the earth's surface, a
§ r eat number of mountain-chains have been formed
suddenly.

" 3dly. All the chains thrown up by a particular
^Volution have one uniform direction, being parallel
to each other within a few degrees of the compass,
ev en when situated in remote regions ; but the chains
thrown up at different periods have, for the most part,
different directions.

cc 4thly. Each ' revolution,' or, as it is sometimes
termed, ' frightful convulsion/ has fallen in with the
^ate of another geological phenomenon ; namely, * the
Passage from one independent sedimentary formation
to another/ characterized by a considerable difference
lr * i organic types/

"5thly. There has been a recurrence of these
Paroxysmal movements from the remotest geological
Periods; and they may still be reproduced, and the
depose in which we live may hereafter be broken by
t^e sudden upthrow of another system of parallel
c hains of mountains.

cc 6thly. We may presume that one of these revo-
lutions has occurred within the historical era, when
^e Andes were upheaved to their present height;
for that chain is the best defined and least obliterated
feature observable in the present exterior configuration
of the globe, and was probably the last elevated.

p 5

322

RELATIVE ANTIQUITY

[Book lV«

u 7thly. The instantaneous upheaving from the
ocean of great mountain masses must cause a violent
agitation in the waters; and the rise of the Andes
may? perhaps, have produced that* transient deluge
which is noticed among; the traditions of so many
nations,

" Lastly. The successive revolutions above men-
tioned cannot be referred to ordinary volcanic forces*
but may depend on the secular refrigeration of the
heated interior of our planet." *

I need not enter here into an examination of &**
these topics, as the discussion of several of them has
been in some degree anticipated in former chapters-
Respecting the alternation of periods of general ^ e "
pose and disorder, I have before suggested that ge°"
logical phenomena indicate merely that each regi° n
of the globe has in succession been a great theatre
of subterranean convulsions, as some districts are n0^>
while others remain at rest. Before we can reason"
ably attribute extraordinary energy to any known cause?
we must be sure that its usual force would be W

adequate, though exerted for indefinite ages, to produce
the effects required.

The geologist, therefore? who assumes that cont**

nents and mountain-chains have been heaved up sud -
denly by paroxysmal violence, may be considered aS
pledging himself to the opinion that the accumulate^
effects of ordinary volcanic forces could never in &*v
series of years produce appearances such as we ^"
ness in the earth's crust. Time and the progress °

* Ann. des Sci. Nat., Septembre, Novembre, et Decern^
1829. Revue Francaise, No. 15. May, 1830. The last edition W
M. de B. is in De la Beche's Manual, 3d. edit. ; and D'Aubu*'
son, Traite de Geognosie, torn. iii. p, 282., 1835.

Ch « XXV.]

OF MOUNrAIN-CHAINS.

323

science can alone decide whether such an assumption
is Warranted, or whether, on the contrary, it does not
spring from two scources of prejudice: — first, the
difficulty of conceiving the aggregate results of a great
^mber of minor convulsions ; secondly, the habit of
dewing geological phenomena without any desire to
explain them as the effects of moderate forces, such
a s we know to act, instead of that intense degree of
e nergy ? the occasional development of which, however
Possible, is entirely conjectural.

The speculation of M.'de Beaumont concerning the
c< secular refrigeration" of the internal nucleus of the
globe, considered as a cause of the instantaneous rise
°f mountain- chains, . appears to me obscure, and is
Mainly founded on that part of the doctrine of central
heat which has been controverted in the secon
Volume.*

In regard to the connection of the rise of mountain-
chains with revolutions equally sudden in the animate
^orld, I have endeavoured to show, in the third book,
that changes in physical geography, which are un-
ceasingly in progress, are among the causes which
contribute, in the course of ages, to the extermination
°f certain species of animals and plants ; but the in-
fluence of these causes is slow, and, for the most part,
^direct, and has no analogy with those sudden cata-
strophes which are introduced into the theory now
u **der review. An explanation of the probable cause
°f the abrupt transitions from one set of strata to
Mother, containing distinct organic remains, has been
§ iv eti at length in the third and fourth chapters of
l his book, f

■

Book ii. chapters xviii. and xix.
f See particularly from p. 345. to p. 355. of Vol. III.

p 6

> ■ * ■

111

324?

RELATIVE ANTIQUITY

[Book IV

When the protrusion of the Andes from beneath the
sea is proposed as a possible cause of the historical
deluge, we naturally inquire, what proofs there are of
that chain having started up at once within the last
4000 or 5000 years from a great depth of sea ; for it * s
necessary that a large body of water should be dis-
placed, in order that a diluvial wave, capable of &*
undating a previously existing continent, should be
raised. If it were reasonable to refer deluges to what
have been called paroxysmal elevations, it would surely
be a fairer speculation to point to a line of shoals o*
reefs, consisting of shattered and dislocated rocks, and
surrounded on all sides by an unfathomable ocean, tha#
to select a mountain-chain as the site of the upthro^'
for the rapid conversion of the bed of a deep sea \xA°
a shoal would evidently cause a much greater displace*
ment of water than the rise of a large shoal into *

shaH

mountain-chain.

Without dilating further on these subjects, I
now endeavour to analyze the proofs by which tltf
successive elevation of different chains, and the sup"
posed parallelism of lines of contemporaneous elev#'
tion, are supported.

M. de Beaumont's proofs that different chains tf ere

raised at different epochs. — "We observe/' says

Elie de Beaumont, "along nearly all the mountain
chains, when we attentively examine them, that th e
most recent rocks extend horizontally up to the foot o*

such chains, as we should expect would be the case *
they were deposited in seas or lakes, of which the$ e
mountains have partly formed the shores ; whilst tb
other sedimentary beds, tilted up, and more or l eS$
contorted, on the flanks of the mountains, rise in cet"

<*. XXV.]

OF MOUNTAIN-CHAINS. ■

325

tain points even to their highest crests/'* There are,
therefore, in and adjacent to each chain, two classes of
sedimentary rocks, the ancient or inclined beds, and
the newer or horizontal. It is evident that the first
a Ppearance of the chain itself was an event " inter-
mediate between the period when the beds now up-
raised were deposited and that when the strata were
Produced horizontally at its feet/'

Fig. 216.

Thus the chain A assumed its present position after
the deposition of the strata &, which have undergone
great movements, and before the deposition of the
group c, in which the strata have not suffered derange-
ment.

If we then discover another chain B, in which we

Fig. 217

*h*d not only the formation 5, but the group c also,
^sturbed and thrown on its edges, we may infer that
l he latter chain is of subsequent date to A; for B
must have been elevated after the deposition of c, and
before that of the group d ; whereas A had originated
be fore the strata c were formed.

Phil. Mag. and Annals, No, 58., New Series, p. 242.

326

RELATIVE ANTIQUITY

[Book IV.

In order to ascertain whether other mountain ranges
are of contemporaneous date with A and B, or are re-
ferable to distinct periods, we have only to inquire

whether the geological phenomena are

identical \

namely, whether the inclined and undisturbed sets 01
strata in each correspond to those in the types above

mentioned.

Objections to M. de Beaumont's theory.

Now

all
the

this reasoning is perfectly correct, so long as
periods of the deposition of the particular local groups
of strata b and c are not confounded with the period
during which the animals and plants found fossil in "
and c may have flourished, and provided also that due
latitude is given to the term contemporaneous ; J° r
this term must be understood to allude, not to *
moment of time, but to the interval, whether brief ° r
protracted, which elapsed between two events, namely
between the accumulation of the inclined and that °*
the horizontal strata.

But, unfortunately, no attempt seems to have bee 11
made to avoid this manifest source of confusion, a n

hence the very terms of each proposition are eq u1 '
vocal ; and the length of some of the intervals l
so vast, that to affirm that all the chains raised * n t
such intervals were contemporaneous, is an abuse °
language.

In order to illustrate this argument, I shall sele c
the Pyrenees as an example. This range of mou* 1 '
tains, says M. de Beaumont, rose suddenly (a un seu
jet*) to its present elevation at a certain "epoch in d' 6

* In the last edition of M. de B.'s system (see note abo ve '
p. 323.), he only speaks of the convulsion which raised the XT
renees, as " one of the most violent which the land of Eur°P
ever experienced."

Ch - XXV.]

OF MOUNTAIN- CHAINS.

327

e ^th's history, namely, between the deposition of the
c halk and that of the tertiary formations; for the
c halk is seen in vertical, curved, and distorted beds on
*he flanks of the chain, while the tertiary formations
* e st upon them in horizontal strata at its base.

The only proof offered of the extreme suddenness
°f the convulsion is the shortness of the time which
*ntervened between the formation of the chalk and

l hat of the tertiary strata. *

Now the beds called chalk on the flanks of the Pyre-
** e es differ widely in mineral composition from the
^hite chalk with flints of England and France ; but as
they contain for the most part the same species of
fossil shells, I grant that they may on that evidence be
^ferred to the cretaceous system, f On the other
Wd, the horizontal tertiary strata at the western end
°f the Pyrenees, near Bayonne, are certainly of the

The reader will find, when he re-

acts on these data, that we can only infer that the
§ r eat movement took place after the cretaceous period
** a d commenced, but we cannot assume that it oc-
Cl *rred after the close of that period. So also we may
Sa y> that the Pyrenees rose before the close of the
Miocene epoch, but not that the event happened
before its commencement We cannot permit M. de
^aumont to exclude the whole of either of these
Periods (the Cretaceous and Miocene) from the pos-
Sl ble duration of that interval during all or any part of
^hich the elevation may have taken place.

* Phil. Mag. and Annals, No. 58., New Series, p. 243.

t The fossils which I collected in company with Captain S. E.
Co °k, R. N., from the newest secondary beds on the flanks of the
Pyrenees, near Bayonne, were examined by M. Deshayes, and
*°Und identical with species of the chalk near Paris.

■

;

■

328

RELATIVE ANTIQUITY

[Book I v «

The upheaving of the Pyrenees, therefore, may have
been going on before the animals of the chalk period

Maestricht

progress

or during the indefinite ages which mtf

Maestri

animals and the introduction of the Eocene tribes, ot
during the Eocene epoch, or between that and the

Miocene

Mio

epoch. Or the rise may have been going on through"
out one, or several, or all of these periods.

It would be a purely gratuitous assumption to s&f
that the chalk strata c, Fig. 217., p. 325., were the la sfc
which were deposited during the cretaceous period, ° r
that, when they were upheaved, all or nearly all thG
species of animals and plants which are now foufld
fossil in them were suddenly exterminated; y et '
unless this can be affirmed, we cannot say that & e
chain B was not upheaved during the cretace° uS
period. Consequently, another range of mountain 5
(A, Fig. 216.), at the base of which cretaceous rock s >
c, may lie in horizontal stratification, may have be eti

elevated during the same period; because, in
case, the particular group c may have been formed \^
after the animals and plants which are characterise
of them, in a fossil state, began to flourish, and durtfte
those antecedent ages the chain A may have risen.

The Newer Pliocene strata in Sicily have be en
raised to the height of nearly 3000 feet in some placed
with great derangement; yet the testacea and z°°*
phytes inclosed in these still exist, or nine tenths ^
^^^^^^ ^^^^^^^^ terranean. The same pe** 10
still continues, if we speak of periods in the same e% '
tended sense in which they are understood by geol°"

gists, and by M. de Beaumont, in the memoir fl°

this

Med

Ch « XXV.]

OF MOUNTAIN-CHAINS.

329

befor
b

e us. So the chalk in the Pyrenees may have
e en raised to the height of many thousand feet, when
^e animals found fossil in the upheaved strata still
c °ntinued to inhabit the sea.

in like manner the sea may have been inhabited by
Miocene testacea for ages before the deposition of
those particular Miocene strata which occur at the
*°ot of the Pyrenees.

To illustrate the grave objections above advanced,
*hich go to affect the whole of De Beaumont's reason-
lri g> let us suppose, that in some country three styles
^architecture had prevailed in succession, each for a
P e riod of one thousand years ; first the Greek, then

6 Roman, and then the Gothic ; and that a tremen-

^Us earthquake was known to have occurred in the
Sat *ie district during one of the three periods, — a con-
cision of such violence as to have levelled to the
§ r ound all the buildings then standing. If an anti-
*i u ary, desirous of discovering the date of the cata-

frophe, should first arrive at a city where several
;* r eek temples were lying in ruins and half engulphed
^ the earth, while many Gothic edifices were stand-

g uninjured, could he determine on these data the
e ^ of the shock ? Could he even exclude any one of

** e three periods and decide that it must have happened
^ring one of the other two? Certainly not. He

° u ld merely affirm that it happened at some period
^ te r the introduction of the Greek style,, and before
y* e Gothic had fallen into disuse. Should he pretend
define the date of the convulsion with greater
decision, and decide that the earthquake must have
°ccurred after the Greek and before the Gothic period,

hat is to say, when the Roman style was in use, the
* ac y in his reasoning would be too palpable to escape

Section for a moment.

nil

330

RELATIVE ANTIQUITY

[Book

IV;

Yet such is the nature of the erroneous induction
which I am now exposing. For as, in the example
above proposed, the erection of a particular edifice lS
perfectly distinct from the period of architecture in
which it may have been raised, so is the deposition °
chalk, or any other set of strata, from the geologic 1
epochs characterized by certain fossils to which they
may belong.

It is superfluous to enter into any farther analysis °
this theory, because the force of the whole argumefl
depends on the accuracy of the data by which th e
contemporaneous or non-contemporaneous date of t* 1
elevation of two independent chains can be demo* 1 '
strated. In every case, this evidence, as stated tv
M. de Beaumont, is equivocal, because he has not ir
eluded in the possible, interval of time between the d e
position of the deranged and the horizontal formatio 1 ^
part of the periods to which each of those classes
formations are referable. By the insufficiency, th^
of the above proofs, the doctrine of the parallelism
lines of contemporaneous elevation is destroyed ; v e
cause all the geological facts may be true, and ) r
the conclusion that certain chains were or were n
simultaneously upraised is by no means a legiti** 1

consequence.

As the hypothesis of parallelism, however, has a
quired some popularity, I may remark, that it app e ^ r
as stated by the author, to be in some degree at variant
with itself. When certain European chains were
sumed to have been raised at the same time, on

ate

data already impugned, it was found that several
these contemporaneous chains had a parallel directs '
Hence it was immediately inferred to be a general

in geological dynamics that the chains upheav

ed*'

Ch - XXV.

]

OF MOUNTAIN-CHAINS.

331

^e same time are parallel. For example, it was said

*jat the Pyrenees and northern Apennines have a

Section about W. N. W. and E. S. E. ; to this line the

^Ueghanies, in North America, conform, as also the

Ghauts of Malabar, and certain chains in Egypt, Syria,

n ° r thern Africa, and other countries; and from this

^e conformity in direction it was presumed that all

^ese mountain-ranges were thrown up simultane-
ously.*

Par

To select another example, the principal chain of
he Alps, differing in age and direction from the Py-
* ei *ees, is parallel to the Sierra Morena, the Balkan,
^ e chain of Mount Atlas, the central chain of the
C ^Ucasus, and the Himalaya. All these ridges, there-
0r e, are assumed to have been heaved up by the same
oxysmal convulsion. The Western Alps, on the
ot W hand, rose at a still earlier period, when the
wall e i chains of Kiol, in Scandinavia, certain chains
^ Morocco, and the littoral Cordillera of Brazil, were
^ftied !

Not only do these speculations refer to mountains
ey er yet touched, as M. Boue remarks, by the ham-
, er of the geologist, but they proceed on the suppo-
l ^°n, that in these distant chains the geological and
^graphical axis always coincide. Now we know
^ a t in Europe the strike f of the beds is not always

^ regard to the Alleghanies, see De Beaumont, 1833. French

rar *s. of De la Beche's Manual, p. 657. But in fact thisthain

**from N. E. to S. W.

T The term " strike" has been recently adopted by some of

, r ^ost eminent geologists from the German " streich," to

S §1 % what our miners call the " line of bearing" of the strata.

0/ * a terin was much wanted ; and, as we often speak of striking

^ ln a given direction, the expression seems sufficiently consistent

analogy in our language.

■

% m

332

RELATIVE ANTIQUITY

[Book

IV,

parallel to the direction of the chain. As an exception?
we may instance the Hartz mountains, where Von D e "
chen* states that the direction or strike of the. strata
of slate and greywacke is sometimes from E. and ™* 9
and frequently N. E. and S. W. ; the geographical dl *
rection of the mountain-chain being decidedly f r0

W.N. W

In addition to these considerations, the impor

tan 1

)

the elevating forces, whose activity must be ref^ re
to different epochs, have sometimes acted in Europ
in parallel lines. " It is worthy of remark," he say
H that the directions of three systems of mounta 1 * 1 '
— namely, first that of the Pilas and the Cote d'0 r '
secondly, that of the Pyrenees ; and thirdly, that
the islands of Corsica and Sardinia, — are respective
parallel to three other systems, namely, first, that

Westmoreland and the Hunsdruck ; secondly, that
the Ballons (or Vosges) and the hills of the BoC&v
in Calvados ; and thirdly, the system of the nortfl
England. The corresponding directions only diflfe r «
a few degrees, and the two series have succee
each other in the same order, leading to the supp

rfP

tftf*

rence of the same, or nearly the same, directions
elevations." \

Here then, we have three systems of moun
A, B, C, which were formed at successive epochs,
have each a different direction : and we have th r
other systems, D, E, F, which, although they are

sumed to have the same strike as the series first & ^

Mied (D corresponding with A, E with B,

* Trans, of De la Beche's Geol. Manual, p. 41.

f Phil. Mag. and Annals, No. 58., New Series, pp- 255:

$56

x r

Ch.

XXV.]

OF MOUNTAIN-CHAINS

333

* xt h C), are nevertheless declared to have been formed
a ' different periods. On what principle, then, is the
a §e of an Indian or transatlantic chain referred to one
°f these European lines rather than to another ?
w hy is the age of the Alleghanies, or the Ghauts of
Malabar, determined by their parallelism to B rather
l han to E, to the Pyrenees rather than to the Ballons

of the Vosges ? *
Modern volcanic lines not parallel. — The analogy of

v °lcanic operations in our own times would lead us to
appose that the lines of convulsion, at former epochs,
^ e re far from being uniform in direction ; for that the
tr ains of active volcanos are not parallel, every one is
aMr are who has studied Von Buch's masterly survey of
the general range of volcanic lines over the globe t;
^hile the elevations and subsidences caused by mo-
7 e Hi earthquakes, although they may sometimes run
111 parallel lines within limited districts, have not been
°bserved to have a common direction in distant and
^dependent theatres of volcanic action.

I doubt not that in many regions, yet only within a
'.United range of country, the ridges, troughs, and fis-
hes caused by modern earthquakes, are, to a certain
e *tent, parallel to each other; and such appears to
^■ve been the case in many districts at former eras.

* The substance of the last objection has been anticipated by
**• Boue" (Journ. of Geol., torn. iii. p. 338. )• I shall not re-
Peat here minor points and facts, enumerated, in a former edition,
as disputed by several geologists, because they are of no import-
ariCe if the basis of the theory is unfounded. See Mr. Cony,
fare's remarks, Phil. Mag. and Journ. of Sci., No. 2., Third
^es, p. 118. Studer, Bulletin de la Soc. Geol. de France, ii.
P* 68.

t Physical. Besch. der Canarischen Inseln. Berlin, 1825.

334.

RELATIVE ANTIQUITY

[Book IV.

Weald

ion

been contemporaneous ; that is to say, both may b ave
been formed in some part of the Eocene period, -^ a
hypothesis which does not involve the theory of the 1
having been due to a paroxysmal convulsion at tfl
same moment of that vast period. It should be o®'
served, that, as some trains of burning volcanos a
parallel to each other, so at all periods some in
pendent lines of elevation may be parallel accidental!/'
not in obedience to any known law of parallelism, b u
on the contrary, as exceptions to the general rule.

The speculations of M. de Beaumont will, I t rUS '
be useful, in inducing geologists to inquire how far *
uniformity in the direction of the beds, in a reg
which has been agitated at any particular period, & *
extend ; but, in the present st^te of our science
cherish no sanguine expectations of fixing a chrofl *
gical succession of epochs of elevation of differ
mountain-chains, or of making more than a loose #P
proximation to such a result. The difficulty depe* 1
chiefly on the broken and interrupted nature of *
series of sedimentary formations hitherto brought
light, which appears so imperfect that we can ve ^
seldom be sure that, between the groups now cl# sS «
as consecutive, the memorials of some great interval
time may not be wanting. Another great source
ambiguity arises from the small progress which
have yet made in identifying strata in countries sort 1

what distant from each other.

tffi e

There may be instances, perhaps, where the s#
set of strata, preserving throughout a perfect idefltw
of mineral character, may be traced continuously * r
the flanks of one independent mountain-chain to

■

Ch « XXV.]

OF MOUNTAIN-CHAINS

335

"ase of another, the beds being vertical or inclined in
0r *e chain, and horizontal in the other. We might
*hen decide with confidence, according to the method
Proposed by M. de Beaumont, on the relative periods
at which these chains had undergone disturbance : and
fr °m one point thus securely established, we might
Proceed to another, until we had determined the eras
of many neighbouring lines of convulsion.

•

:;.

336

CHAPTER XXVI.

ON THE ROCKS COMMONLY CALLED " PRIMARY.

Relation of rocks called " Primary" to volcanic and sedime* 1 a
formations — Unstratified rocks called " Plutonic" — ■ ^ aD
veins — Their various forms and mineral composition — ■ * r
of their igneous origin — Granites of the same character P
duced at successive eras (p. 343.) — Some of these newer
certain fossiliferous strata — Volcanic, trappean, and pl ut
rocks.

I shall now treat of the class of rocks usually tert* 1

a name which, as I shall afterwards sh°

" primary,

is not always applicable, since the formations so de s b
nated sometimes belong to different epochs, and a
not, in every case, more ancient than the fossilif er °
strata. In general, however, this division of rocks & ;
justly be regarded as of higher antiquity than .
secondary and transition groups above described ; a
they may, therefore, with propriety be spoken ot

oft

these concluding chapters, as I have hitherto procee
in my retrospective survey from the newer to the &
ancient geological monuments.

In order to explain the relation which I con cel
the rocks termed " primary " to bear to the terti* V
secondary, and transition formations, I shall res u
that general view of the component parts of the ea r
crust of which I gave a slight sketch in the p r
minary division of the subject in the second chapt* •

* See Vol. III. pp. 313, 314.

Ch - XXVI.]

PLUTONIC ROCKS.

337

It was there stated that sedimentary formations,
containing organic remains, occupy a large part of the
surface of our continents ; but that here and there vol-
canic rocks occur, covering, alternating with, or break-
ln g through, the sedimentary deposits ; so that there
ar e two orders of mineral masses formed at the surface

w hich have obviously a distinct origin,
an d the volcanicJ

the aqueous

Fig. 218.

a_^

a - Formations called primary (stratified and unstratified\
b ' Aqueous formations. c. Volcanic rocks.

Besides these, however, there is another class, which
c annot be assimilated precisely to either of the pre-
ying, and which is often seen underlying the sedi-
mentary, or breaking up to the surface in the central
Parts of mountain-chains, constituting some of the
f "ghest lands, and, at the same time, passing down and
<*ming the inferior parts of the crust of the earth.
t hl « class, usually termed "primary," is divisible into
*o groups,— the stratified and the unstratified. The
Ratified consists of the rocks called gneiss, mica-schist,

filaceous-schist (or clay-slate), hornblende-schist!
J lf nary limestone, and some others. The unstratified,
J\ Plutonic > is composed in great measure of granite,
^ d rocks closely allied to granite. Both these groups
t § r ee in having, for the most part, a highly crystalline

x *ure, and in not containing organic remains.

m^J f .mm —

Plutonic rocks.

The unstratified crystalline rocks

ave been very commonly called Plutonic, from the

V( H. IV.

■ 4

338

GRANITE VEINS.

[Book

IV.

opinion that they were formed by igneous action at
great depths ; whereas the volcanic, although they als°
have risen up from below, have cooled from a melted
state upon or near to the surface. Granite, porphyry?
and other rocks of the same family, often occur tfj
large amorphous masses, from which small veins afl
dikes are sent off, which traverse the stratified rocks
called "primary," precisely in the manner in which
lava is seen in some places to penetrate the secondary
strata.

Granite veins. — We

ies

veins intersecting another, and granitiform porphyr
intruding themselves into granite, in a manner analo*
gous to that of the volcanic dikes of Etna and Vestf*
vius, where they cut and shift each other, or p
through alternating beds of lava and tuff.

a$$

Fig. 219.

Granite veins traversing stratified rocks.

The annexed diagram will explain to the reader t
manner in which these granite veins often branch
from the principal mass. Those on the right-h** 11

„:j~ „»A ,'r, tho vni'rMlp nrp tnlrpn frnm Dr. MacCU '

■

Cl >- XXVI.]

GRANITE VEINS.

339

^ch's representation of veins

passing through the

gneiss at Cape Wrath, in Scotland.* The veins on
the left of the same diagram are described, by Captain
Basil Hall, as traversing the argillaceous schist of the
Table-Mountain at the Cape of Good Hope.f

I subjoin another sketch from Dr. MacCulloch
teresting representations of the granite veins in Scot-
land, and in which the contrast of colour between th

Fig- 220,

^^^^^^^H

1
1

s in-

Granite veins traversing gneiss at Cape_ Wrath, in Scotland.

v ein and some of the dark varieties of hornblende-
Schist associated with the gneiss renders the phenomena
"fiore conspicuous.

The following sketch of a group of granite veins in
Cornwall is given by Messieurs Von Oeynhausen and
y on Dechen. % The main body of the granite here is
of a porphyritic appearance, with large crystals of M-
s Par ; but in the veins it is fine-grained, and without
"ese large crystals. The general height of the veins

J s from sixteen to twenty feet, but some are much
hl gher.

■ Western Islands, plate SI.

+ Account of the Structure of Table- Mountain, &c. Trans.
n °y- Soc. Edin., vol. vii.

* p hil. Mag. and Annals, No. 27., New Series, March,

1829.

Q 2

^^-*-

"•.

340

GRANITE VEINS.

[Book

IV.

Fig. 221.

Granite veins passing through hornblende slate, Carnsilver Cove, Cornwall'

The vein-granite of Cornwall very generally assuifl^
a finer grain, and frequently undergoes a change in
mineral composition, as is very commonly observed *#
other countries. Thus, according to Professor Sedg'
wick, the main body of the Cornish granite is an %%'
gregate of mica, quartz, arid felspar ; but the veins a re
sometimes without mica, being a granular aggregate
of quartz and felspar. In other varieties quartz p re '
vails to the almost entire exclusion both of felspar Qfl a
mica ; in others, the mica and quartz both disapp eaf '
and the vein is simply composed of white granule
felspar.*

Changes are sometimes caused in the intersect^
strata very analogous to those which the contact ot *■
fused mass might be supposed to produce.

The annexed diagram, from a sketch of Dr. M^ c "
Culloch, represents the junction of the granite of G* en
Tilt, in Perthshire, with a mass of stratified limestone

* On Geol. of Cornwall, Trans, of Cambridge Soc, ▼

oh 1

. 124.

t >i^

c h. XXVI.] JUNCTION OF GRANITE AND LIMESTONE. 341

and schist. The granite, in this locality, often sends
forth so many veins as to reticulate the limestone and
schist, the veins diminishing towards their termination
to the thickness of a leaf of paper or a thread. In
s ome places fragments of granite appear entangled, as it
w ere, in the limestone, and are not visibly connected
w ith any larger mass ; while sometimes, on the other
hand, a lump of the limestone is found in the midst of
l he granite. The ordinary colour of the limestone of

Fig, 222.

Junction of granite and limestone in Glen Tilt.

a. Granite.

& Blue argillaceous schist.

b. limestone

e n Tilt is lead blue, and its texture large-grained

ai *d highly crystalline ; but where it approximates to

Q 3

- .

•• -

-. ■♦ . .

„ _ * ■

■

3*2

GRANITE VEINS.

[Book I v -

the granite, particularly where it is penetrated by the
smaller veins, the crystalline texture disappears, and it
assumes an appearance exactly resembling that 01

hornstone.

The associated argillaceous schist often

passes into hornblende slate, where it approaches very
near to the granite.*

The conversion of the limestone in these and many
other instances into a siliceous rock, effervescing

slowly with acids, would be difficult of explanation, were
it not ascertained that such limestones are always in 1 "
pure, containing grains of quartz, mica, or felsp& r
disseminated through them. The elements of these
minerals, when the rock has been subjected to great
heat, may have been fused, and so spread more uni'
formly through the whole mass.

In the plutonic, as in the volcanic rocks, there lS
every gradation from a tortuous vein to the most re'
gular form of a dike, such as I have described inter*
secting the tuffs and lavas of Vesuvius and Etna. ^ n
these dikes of granite, which may be seen, among

other places, on the southern flank of Mount Battocn
one of the Grampians, the opposite walls sometimes
preserve an exact parallelism for a considerable diS"
tance. It is not uncommon for one set of granite vein
to intersect another ; and sometimes there are thre
sets, as in the environs of Heidelberg, where tn e
granite on the banks of the river Necker is seen i0
consist of three varieties, differing in colour, grain, a n
various peculiarities of mineral composition. One °
these, which is evidently the second in age, is seen *
cut through an older granite ; and another, still newer?
traverses both the second and the first. These pheno*

* MacCulloch, Geol. Trans., vol. iii. p. 259

• \

Ch. XXV I.]

GRANITES OF DIFFERENT AGES.

343

*nena were pointed out to me by Professor Leonhard

at Heidelberg.

In Shetland there are two kinds of granite. One
of these, composed of hornblende, mica, felspar, and
quartz, is of a dark colour, and is seen underlying
gneiss. The other is a red granite, which penetrates
the dark variety every where in veins. *

Granites of different ages.— It was formerly supposed
that granite was the oldest of rocks, the mineral pro-
duct of a particular period or state of the earth, formed
long antecedently to the introduction of organic beings
into our planet. But it is now ascertained that this
rock has been produced again and again, at successive
eras, with the same characters, penetrating the stra-
tified rocks in different regions, but not always asso-
ciated with strata of the same age. Nor are organic
remains always entirely wanting in the formations in-
vaded by granite, although they are usually absent.
Many well-authenticated exceptions to the rule
now established, on the authority of numerous ob-
servers, amongst the earliest of whom we may cite

Von Buch, who discovered in Norway a mass of granite
overlying an ancient secondary limestone, containing
orthocerata and other shells and zoophytes, f

A considerable mass of granite in the Isle of Sky is
described by Dr. MacCulloch as incumbent on lime-
stone and shale, which are of the age of the English
Has. J The limestone, which, at a greater distance
from the granite, contains shells, exhibits no traces of

* MacCulloch, Syst. of Geol., vol. i. p. 58.

t Travels through Norway and Lapland, p. 45. London,

1813.

t See Murchison, Geol. Trans., Second Series, vol. ii. partii.

pp. 311—321.

are

Q 4

-4

344

GRANITES OF DIFFERENT AGES.

[Book IV.

them near its junction, where it has been converted
into a pure crystalline marble.* r

This granite of Sky was at first termed " Syenite/'
by which name some authors have denominated the
more modern granites ; but they have entirely failed
in their attempt to establish a distinction between
granites and syenites on geological grounds. Syenite
has been defined to be a triple compound of felspar
quartz, and hornblende ; but the oldest granitiform
rocks are very commonly composed of these ingre-
dients only. In his later publications Dr.
loch has, with great propriety, I think, called the
plutonic rock of Sky a granite, f

In different parts of the Alps a comparatively modern

Mac

granite is seen penetrating through secondary strata?
which contain belemnites, and other fossils, and are
supposed to be referable to the age of the English

lias.

Beaumont and Hugi, masses of this granite are some-
times found partially overlying the secondary beds?

in a manner analagous to

the

and altering them

changes superinduced upon sedimentary deposits in

)

x ( s

In such examples we can merely affirm, that the
granite is newer than a secondary formation containing
belemnites ; but we can form no conjecture when i t
originated, not even whether it be of secondary or ter-
tiary date. It is not to be inferred that a granite is

* Western Islands, vol. i. p. 330.

f Syst. of GeoL, vol. i. p. 150.

\ Elie de Beaumont, sur les Montagues de l'Oisans, Mem. de
la Soc. d'Hist. Nat. de Paris, tome v. Hugi, Natur. Historiscbe
Alpenreise, Soleure, 1830.

ChXXVL]

TRAP ROCKS.

345

usually of about the same age as the group of strata
into which it has intruded itself; for in that case we
should be inclined to assume, rashly, that the granite
found penetrating a more modern rock, such as the
has, for example, was much newer than that which
*s found to invade greywacke. The contrary may
°ften be true ; for the plutonic rock which was last in
a melted state may not anywhere have been forced
u p so near to the surface as to traverse the newer
groups, but may be confined exclusively to the older
Sedimentary formations.

" In a deep series of strata," says Dr. MacCulloch,
u the superior or distant portions may have been but
s %htly disturbed, or have entirely escaped disturb -
ar *ce, by a granite which has not emitted its veins far
eyond its immediate boundary. However certain,
therefore, it may be, that any mass of granite is pos-
terior to the gneiss, the micaceous schist, or the argil-
,a ceous schists, which it traverses, or into which it
lr Urudes, we are unable to prove that it is not also pos-
terior to the secondary strata that lie above them."*

There can be little doubt, however, that some gra-
ces are more ancient than any of our regular series
^hich we identify by organic remains ; because there
ar e rounded pebbles of granite, as well as gneiss, in
the conglomerates of very ancient fossiliferous groups.

Distinction between volcanic and plutonic rocks
rap — When geologists first began to ekamine at-
tentively the structure of the northern parts of Europe,
&e y were almost entirely ignorant of the phenomena

existing volcanos ; and when they met with basalt

* Syst. of Geol., vol. 1. p. 136

Q 5

• \

TRAP ROCKS.

[Book

klV

and other rocks composed chiefly of augite, hornblende
and felspar, which are now admitted by all to have
been once in a state of fusion, they were divided »P
opinion whether they were of igneous or of aqueous
origin. In the sketch of the history of geology in the
first volume, it was shown how much the polemics
controversies on this subject retarded the advance-
ment of the science, and how slowly the analogy °
the rocks in question to the products of active volcanos

was recognized.

Most of the igneous rocks first investigated in Ger-
many, France, and Scotland were associated with ma-
rine strata, and in some places they occurred in tabula'
masses or platforms at different heights, so as to fort"
on the sides of some hills a succession of terraces o»
steps; from which circumstance they were calle
" trap" by Bergman (from trappa, Swedish for a nig' 1
of steps), — a name afterwards adopted very generally
into the nomenclature of the science.

When these trappean rocks were compared wit 1
lavas produced in the atmosphere, they were found t°
be in general less porous and more compact : and fro
this character, and their association with subaqueo u
deposits, the connection of their origin with ordinal
volcanic action was overlooked. In this instance to
terms of comparison were imperfect; for a set of roc '
formed almost entirely under water, was contraste
with another which had cooled in the open air. ^

Yet the products of the ancient volcanos of Cen r
France were classed, in reference, probably, to tn e ^
antiquity, with the trap rocks, although they aP° T ^
perfect counterparts to existing volcanos, and je
evidently formed in the open air. Mont Dor and ^
Plomb du Cantal, indeed, differ in many respects v°

Ch. XXV I.]

RAP ROCKS.

347

Vesuvius and Etna in the mineral constitution and
structure of their lavas ; but it is that kind of differ-
ence which we must expect to discover when we com-
pare the products of any two active volcanos in distant
regions, such as Teneriffe and Hecla, or Hecla and
Cotop

axi.

The amygdaloidal structure in many of the trap
formations proves that they were originally cellular
and porous, like lava; but the cells have been subse-
quently filled up with silex, carbonate of lime, zeolite,
and other ingredients which form the nodules. The
absence of this amygdaloidal structure may be said to
be one of the negative characters of granite and other
plut

onic r

ocks.

Dr. MacCulloch, after examining with great atten-
tion the igneous rocks of Scotland, observes, " that it
*s a mere dispute about terms to refuse to the ancient
eruptions of trap the name of submarine volcanos, for
l hey are such in every essential point, although they
**o longer eject fire and smoke/"* The same author
also considers it not improbable that some of the vol-
canic rocks of the same country may have been poured
°ut in the open air. f

The recent examination of the igneous rocks of
Sicily, especially those of the Val di Noto, has proved
that all the more ordinary varieties of European trap
^ave been produced under the waters of the sea in the
^ewer Pliocene period ; that is to say, since the Me-
^terranean has been inhabited by a great proportion
°* the existing species of testacea. We are, therefore,
^titled to expect, that if we could obtain access to
^e existing bed of the ocean, and explore the igneous .

* Syst. of Geo!., vol. ii. p. 114.

Q 6

f Ibid

* .; ■/•

348

RELATIONS OF GRANITE AND TRAP.

[Book IV

■*

)

volcano,

rocks poured out within the last five thousand years
beneath the pressure of a sea of considerable depth
we should behold formations of modern date very
similar to the most ancient trap rocks of our island*
We cannot, however, expect the identity to be perfect;
for time is ever working some alteration in the com-
position of these mineral masses, as, for example, by
converting porous lava into amygdaloids.

Passage from trap into granite. — If a division v e
attempted between the trappean and volcanic rocks, i*
must be made between different parts of the sam e

— nay, even the same rock, which would b e
called " trap," where it fills a fissure and has assumed
a solid crystalline form on slow cooling, must v e
termed volcanic, or lava, where it issues on the flanks
of the mountain. Some geologists may, perhaps, ^ e
of opinion that melted matter, which has been pour^
out in the open air, may be conveniently called vol"
canic ; while that which appears to have cooled at th e
bottom of the sea, or under pressure, but at no gre^
depth from the surface, may be termed " trap:" but **
is very doubtful whether such distinctions can be m^ e
without confusion, and whether we shall not be oblig e
to consider trap and volcanic as synonymous. On w e
other hand, the difficulty of discriminating the volcafl lC
from the plutonic rocks is sufficiently great ; th#" e
being an insensible passage from the most comm 0l)
forms of granite into trap or lava.

" The ordinary granite of Aberdeenshire," say
Dr. MacCulloch, « is the usual ternary compound o*
quartz, felspar, and mica; but sometimes hornblefl^
is substituted for the mica. But in many places

variety occurs which is composed simply of felspar an

in examining more minutely ^ l

hornblende ; and

Ch.XXVL] RELATIONS OF GRANITE AND TRAP.

349

duplicate compound, it is observed in some places to
assume a fine grain, and at length to become undistin-
guishable from the greenstones of the trap family. It
a lso passes in the same uninterrupted manner into a
basalt, and at length into a soft claystone, with a
schistose tendency on exposure, in no respect dif-
fering from those of the trap islands of the western
coast."* The same author mentions, that in Shetland
a granite composed of hornblende, mica, felspar, and
quartz graduates in an equally perfect manner into
basalt, f

It would be easy to multiply examples to prove that
the granitic and trap rocks pass into each other, and
are merely different forms which the same elements
bave assumed, according to the different circumstances
Under which they have consolidated from a state of
fusion. What has been said respecting the mode of
explaining the different texture of the central and ex-
ternal parts of the Vesuvian dikes may enable the
deader in some measure to comprehend how such dif-
ferences may originate. J

The lavas, which are porous where they have flowed
°ver the crater, and cooled rapidly under compara-
tively slight pressure, appear compact and porphyritic
XI * the dike. Now these dikes evidently communicate
w ith the crater and the volcanic foci below ; so that
w e may suppose them to be continuous to a vast
depth; and the fluid matter below, which cools and
consolidates slowly under so enormous a pressure,
^ay be conceived to acquire a very distinct and more
cr ystalline texture, like granite.

If it be objected that we do not find in mountain-

Syst. of Geol., vol. i. p. 157.

f Ibid., p. 158

I See p. 8.

• ■ - ■ ■

350

ORIGIN OF GRANITE.

[Book

IV.

chains volcanic dikes passing upwards into lava, and
downwards into granite, we may answer, that our ver-
tical sections are usually of small extent ; and if we
find in certain places a transition from trap to porous
lava, and in others a passage from granite to trap, it lS
as much as could be expected of this evidence. I*
should also be remembered, that a large proportion of
the igneous rocks, when first formed, cannot be sup'
posed to reach the surface, and these may assume tW
usual granitic texture without graduating into trap, ° r
into such lava and scoriae as are found on the flanks o*

a volcanic cone.

of the origin of granit

It is

not uncommon for lava streams to require more thai 1
ten years to cool in the open air; and where they a re
of great depth, a much longer period. The melted
matter poured from Jorullo, in Mexico, in the ye# r
1759, which accumulated in some places to the heigb*
of 550 feet, was found to retain a high temperature
half a century after the eruption.* For what immense
periods, then, may we not conceive that great masses
of subterranean lava in the volcanic foci may rema in
in a red-hot or incandescent state, and how graduB*
must be the process of refrigeration ! This process
may be sometimes retarded for an indefinite period?
by the accession of fresh supplies of heat; for we fi n(J
that the lava in the crater of Stromboli, one of t' ie
Lipari islands, has been in a state of constant ebulliti° n
for the last two thousand years ; and we must suppo se
this fluid mass to communicate with some cauldron of

■

reservoir of fused matter below. In the Isle of Bourbon*
also, where there has been an emission of lava once in

■ ■

* See Vol. II. p. 134.

C h. XXVI.]

ORIGIN OF GRANITE.

351

every two years for a long period, we may infer that
the lava below is permanently in a state of lique-
faction.

The great pressure of a superincumbent mass, and

exclusion from contact with the atmosphere, and per-
haps with the ocean, are some of the conditions which
*nay be necessary to produce the granitic texture ; but
^hat I have before said of the causes of volcanic heat
operating at considerable depths, will show how com-
plicated may be the processes going on in the interior
°f the earth, and how different from any within the
sphere of our observation at the surface.*

If plutonic rocks, such as granite or porphyry, have
originated far below as often as the volcanic have been
generated at the surface, it will follow that no small
quantity of the former class has been forming in the
decent epoch ; since we suppose that about two thou-
sand volcanic eruptions may occur in the course of
every century, either above the waters of the sea or

beneath them.f

We may also infer, that during each preceding
Period, whether tertiary or secondary, there have been
granites and granitiform rocks generated ; because we
have already discovered the monuments of ancient
v olcanic eruptions of almost every period.

In the next chapter I shall endeavour to show, that,
hi consequence of the great depths at which the plu-
tonic rocks usually originate, and of the manner in
^hich they are associated with the older sedimentary
strata of each district, it is rarely possible to determine
w ith exactness their relative age. It may be true that
the greater portion of them now visible are of higher

* Book ii. chapters 18. and 19.

f See Vol. II. p. 178.

352

AGE OF PLUTONIC ROCKS.

[Book l v

antiquity than the oldest secondary strata; and yet
they may have been produced in nearly equal quanti-
ties during equal periods of time, from the earliest to
the most modern epochs, instead of diminishing * n
quantity at each successive epoch, as some geologists
pretend.

353

■

CHAPTER XXVIL

ON THE STRATIFIED ROCKS CALLED " PRIMARY."

"heiher any "primary" rocks are truly stratified — Difference
between stratification and cleavage — Professor Sedgwick on the
Slaty and the Jointed Structure — Alteration of sedimentary
strata by dikes (p. 364.) — Manner in which heat may be con-
Ve yed through rocks — Conversion of sedimentary into crystal-
line strata — The term " Hypogene" proposed as a substitute for
<c primary" (p. 379. ) — " Metamorphic" for u stratified primary"
**ocks — No regular order of succession of hypogene rocks —
Cause of the high relative antiquity of visible hypogene forma-
tions (p. 383.) — They may have been produced at each succes-
s *ve period in equal quantities — Volume of hypogene rocks
Su pposed to have been formed since the Eocene period- — Con-
c *uding remarks.

ether any primary rocks are stratified, — It has been

t&ted that the rocks usually called " Primary," are
visible into the stratified and the unstratified; but
°ttie geologists have entertained doubts as to the pro-
ity of applying the term stratified to any rocks of
*s crystalline or " primary " class. They admit that
e latter are often made up of t&bular masses, or beds
ac ed one upon the other, something in the manner

true strata ; but they deny that the analogy is so

^ er fect as to indicate a similarity of origin : in other

0r( ls, they do not believe the distinct beds into which

y^talline rocks, such as gneiss, mica-schist, andhorn-

e ttde-schist, are divided, to have been the result of

lr *ientary deposition from water.

•

i§

; ■

354

CLEAVAGE OR SLATY STRUCTURE.

[Book

IV.

Now it must be conceded that even in rocks whic* 1
are unequivocally of sedimentary origin, and whic
contain organic remains, there are many lines of P ar

ing, that might easily be mistaken for strata, yet

whid 1

have no connection with stratification. Of these p af
ings some' have been distinguished by miners und e
the name of "joints," others by that of the "planes °
cleavage."

Cleavage or slaty structure. — In an admirable essfy
recently published on this subject, Professor Sedg^ lC

has described the ordinary forms, and speculated °
the probable origin, of these different kinds of str u
ture.* His descriptions are derived from an extens 1

series of original observations, made on the slate yo

ck*

de-
tain

of Cumberland and Wales, and will be read by all ^
are desirous of obtaining a clear and thorough kfl°
ledge of this important class of phenomena.

Some of these Cumbrian and Welsh rocks are
cidedly of mechanical origin ; and some strata con
marine organic remains, so that they must have b e
deposited from water. But, besides being strati* 16
they are intersected by cleavage planes, which a
usually inclined at a very considerable angle to

flC e

planes of the strata, and appear to be in no insta
exactly coincident with them. In some cases
difference is so small that these planes might easflj
supposed parallel ; but their inclination to each <> tl1
in the Welsh chains, is upon an average as mud 1 ^
30° to 40°, Sometimes the cleavage planes dip to^ r
the same point of the compass as those of stratificat*
but more frequently they dip to opposite points. „
" In that variety of slate which is used for roofi*#

* Geol. Trans., vol. iii. Second Series, p. 461

Ch - XXVII.

]

CLEAVAGE OR SLATY STRUCTURE.

355

Sa ys Professor Sedgwick, " the structure of the rock
has been so modified that the traces of its original de-
Position are quite obliterated; and this remark does
^t apply merely to single quarries, but sometimes to
w We mountains. We can, however, in many slate
parries, and even in hand specimens of slate, discover
a number of parallel stripes, sometimes of a lighter, and
s °nietimes of a darker colour than the general mass;
ar *d in rocks of the age I am considering, these stripes
ar e universally parallel to the true bedding of the rocks.
The proof of this is established by the fact that the
Assumption leads to consistent results ; that these
str ipes are always parallel to true beds whenever such
^ds can be discovered, whether by organic remains, by
t]l e alternations of dissimilar deposits, or by any other
° r dinary means. Sometimes, however, all these means
^1> and we may ramble for miles among mountains of
^ate without seeing a single trace of their original
Ratification.
"1 think it obvious," continues the same author,
that the contortions of slate rocks are phenomena
Si^ite distinct from cleavage, and that the curves pre-

8e nted by such formations are the true lines of dis-
ced strata. 9 ' *
In the accompanying section, given by the Professor

Fig. 223.

Parallel planes of cleavage intersecting curved strata.

to illustrate these appearances in the Welsh slate rocks,
u>e see the cleavage planes preserving an almost geo-

«■

Sedgwick, Geol. Trans., vol, iii. Second Series, p. 474.

I !

356

CLEAVAGE OR SLATY STRUCTURE.

[Book

IV.

tra»

)

metrical parallelism, while they pass through contorte
strata of " hard greenish slate, obviously of sedimen *
ary origin.'' A region more than thirty jniles in leng*
and eight to ten in breadth, exhibits this structure ° n
a magnificent scale. Many of the contorted
" are of a coarse mechanical structure ; but subordina
to them are fine, crystalline, chloritic slates. But tn
coarser beds and the finer, the twisted and the straig* 1
have all been subjected to one change.

" The slaty cleavage, however, is only brought out 1
perfection where the materials of the rock are fine an
homogeneous. Yet although the coarser beds are n°
slaty, they are said to have usually a grain parallel
the cleavage planes of the finer beds, and it is on )
when the materials are very coarse that the cleavag
planes entirely vanish."* .

It is admitted by Professor Sedgwick, that some be
of greywacke are subdivided into very thin lam in
which resemble slate, and are used for the same p ur '
poses, yet have been produced by aqueous deposit! 011 '
Nay, in certain cases, " these laminae cannot be disti
guished by their mineral structure from the slates
cleavage." It is proposed, however, to call such slat ;
of deposition "flagstones," by reference to their se
mentary origin. A flagstone, it is said, may general;
be distinguished from a true slate of cleavage by sug .
deviations in its plane ; occasionally by what is cal*
the ripple mark ; by a dull granular surface ; by sca
tered flakes of mica, entirely unlike the continue
chloritic flakes of a true cleavage ; and sometimes
organic remains studded on its surface.

Some confusion will, I fear, arise from attempting

restrict the term slate to those cases alone where

* Proceedings of Geol. Soc. No. 44. p. 360.

the

•

Ch - XXVII.] CLEAVAGE OR SLATY STRUCTURE.

357

slat

v laminae are oblique to the stratification; espe-

Cla % as we have seen that diagonal lamination may be
Produced by sedimentary deposition, and that too in
Sor *)e instances with considerable regularity. But,
whatever nomenclature we adopt, it is clfcar that three
Satinet forms of structure are exhibited in certain
r °cks throughout large districts : viz. — first, stratifi-
Ca tion ; secondly, joints ; and thirdly, slaty cleavage ;
^e two last having no connection with true bedding,
ar *d having been superinduced by causes absolutely in-
^pendent of gravitation. All these different structures
^Ust have different names, even though there be some
Ca ses where it is impossible, after carefully studying the
Phenomena, to decide upon the class to which they

bel

ong.

Before treating of joints, it may be well to speak of
^ e probable origin of slaty cleavage in those cases
^here it is decidedly unconnected with sedimentary
^position. Professor Sedgwick is of opinion that " no
% e treat of parts, no contraction in dimensions, in pass-
es to a solid state, can account for the phenomenon."
j* ttiust be referred to crystalline or polar forces acting
^ultaneously and somewhat uniformly, in given di-
ctions, on large masses having a homogeneous com-
mon.

c There is at first sight a difficulty in comprehending
6 fastness of those forces which nature must have

PpKed in producing such effects. But, in crystalliza*
° n > there is something like a definite polarity in each
l^ticle, by which it is compelled to turn in a given
| re ction, and group itself with other particles in defi-
l * e forms ; and if this modification of internal structure

carried on through a very large mass of matter, is it
ot probable that there is an accumulated intensity of

358

JOINTED STRUCTURE IN ROCKS.

[Book

clV

crystalline action in each part, so that the whole inten-
sity of crystalline force modifying the mass is n °
equal to the sum of the forces necessary to crystals
each part independently, but is some function of tha
sum, whereby it may be increased almost indefinitely •
I see nothing improbable in this kind of accumulate

attraction."*

Sir John Herschel, in allusion to this subject, h*j
suggested to me, " that if rocks have been so heate^
as to allow a commencement of crystallization ; that
to say, if they have been heated to a point at whic 1
the particles can begin to move amongst themselves, °
at least on their own axes, some general law must th^
determine the position in which these particles * l
rest on cooling. Probably, that position will have so&
relation to the direction in which the heat escape '
Now, when all, or a majority of particles of the sal* 1
nature have a general tendency to one position, tb
must of course determine a cleavage plane,
we see the infinitessimal crystals of fresh precipita te
sulphate of baryte, and some other such bodies, arran^
themselves alike in the fluid in which they float ; so ** >
when stirred, all to glance with one light and give t
appearance of silky filaments. Some sorts of soap
which insoluble margarates exist, exhibit the sa
phenomenon when mixed with water ; and what occ&
in our experiments on a minute scale, may occur
nature on a great one, &c." t

Jointed structure. — " Besides the planes of c .
age," observes Professor Sedgwick, " we often find
large slate quarries one or more sets of cross j<> in

* Sedgwick, Geol. Trans., vol. iii. Second Series, pp. 47 h
f Letter to the author, dated Cape of Good Hope, Feb'

1836.

Thu 5

Cb - XXVII.

JOINTED STRUCTURE IN ROCKS.

359

w hich, combined with cleavage, divide the rock into
fhombohedral solids. These solids are not capable of
^definite subdivision into similar solids, except in one
Section, namely, that of true cleavage ; and in this
Wa y> even in hand specimens, we may generally dis-
* n guish the true cleavage planes from the joints.

hese last are fissures placed at definite distances from
° ac h other, the masses of rock between them having,
generally speaking, no tendency to cleave in a direc-
l0t * parallel to them. Such a structure seems in most
Cas es to have been produced mechanically, either by a
* r ain upon the rock from external force, producing
^ore or less regular sets of cracks and fissures, or by
j- Mechanical tension on the mass, produced probably

J" contraction, during its passage from a fluid, or semi-

u *d, into a solid state. Cleavage planes are, on the

0r *trary, the results of the ultimate chemical arrange-

er *t of the particles of a rock, and appear in most

* s es to be unconnected with any direct mechanical

c A slaty and jointed structure are, however, often
***ft>ited together; and cases may arise where it is
Most impossible to decide whether a certain set of
^res are to be called joints, or cleavage planes : but

exception, and not

J^culties of this kind are the

e mle."*

. *he jointed structure is common both to the strati-
G( *and unstratified rocks ; but is best seen in the un-
ratified, as in granite, or columnar basalt In the
^ss and Savoy Alps, Mr. Bakewell has well remarked
at enormous masses of limestone are cut through so
Snarly by nearly vertical partings, and these are

Sedgwick, Geol. Trans., vol. iii. Second Series, pp. 480, 481.

■

•

360

JOINTED STRUCTURE IN ROCKS.

[Book

iv.-

often so much more conspicuous than the seam s
stratification, that an unexperienced observer will a "
most inevitably confound them, and suppose the stra

aim

to be perpendicular when in fact they are
horizontal. * .

The cause of this tendency to a jointed structure
by no means understood ; but it appears, from rece°
observations, that ice sometimes presents a sim lIa
arrangement of parts. Scoresby, indeed, when spea
ing of the icebergs of Spitzbergen, had long ago state >
" that they are full of rents, extending perpendicular;
downwards, and dividing them' into innumerable c °
lumns." Colonel Jackson has lately investigated tj 11
subject more attentively, and has found that the lC
on the Neva, at St. Petersburg, at the beginning
a thaw, when two feet in thickness, is traversed J
rows of very minute air-bubbles extending in straig
lines, sometimes a little inflected, from the upper s u
face of the ice towards the lower, within from W°
five inches of which they terminate. " Other blo c
presented these bubbles united, so as to form cy
drical canals, a little thicker than a horse-hair. ^
serving still further," he says, " I found blocks in

wbi*

the process was more advanced, and two, three
more clefts, struck off in different directions from

or
the

vertical veins, so that a section perpendicular to
vein would represent in miniature the star-for** 1
cracks of timber. Finally, in some pieces, th e ^
cracks united from top to bottom of the veins, sep
ating the whole mass into vertical prisms, having ■

o In this state a slig

shock was sufficient to detach them ; and the W

greater or less number of sides.

* Introduction to Geology, chap, iv

C1 >. XXVII.]

GRANITIC SCHISTS.

361

w ith its scattered fragments was in all respects the
e *act miniature resemblance, in crystal, of a Giant's
Causeway. The surface was like a tessellated pave-
^ent, and the columns rose close, adhering and pa-
rallel, from the compact mass of a few inches at the
Ul *der surface. More or less time is required for the
Process, which I have since seen in all its different

■

stages."*

tification of

If we examine

§fleiss, which consists of the same materials as granite
0r mica-schist, which is a compound of quartz and mica
°r hornblende schist, which is formed of hornblende and
felspar, or any other member of the so-called primary
^vision, we find that they are each made up of a suc-
cession of beds, the planes of which are, to a certain
e *tent, parallel to each other in a manner analogous to
^at exhibited by sedimentary formations of all ages.
They may occasionally exhibit, in addition, both a
Jointed and a slaty structure ; but they are also divided
j&to uneven foliated layers, or in some cases into thick
° e ds which resemble strata of deposition.

The resemblance to stratification in the granitic
Sc hists often extends very far ; for the beds are oc-
casionally contorted, or they are made up of lamina?
Pkced diagonally, as in many sedimentary formations
e fore described f , such laminae not being regularly
Parallel like the planes of cleavage.

This disposition of the layers is illustrated in the
Accompanying diagram, in which I have represented
Penally the stratification of a coarse argillaceous
Sc hist, which I examined in the Pyrenees, part of
W hich approaches in character to a green and blue

* Journ. of Roy. Geogr. Soc, vol. v. p. 19. \\

■

f See above, p. 79.

v ol. iv.

*■•"'

362

GRANITIC SCHISTS

[Book IV.

Fig. 224,

•i

■

Lamination of clay-slate, Montagne de Seguinat, near Gavarnie, in i^ e

Pyrenees.

roofing slate, while part is extremely quartzose, the
whole mass passing downwards into micaceous schist'
The vertical section here exhibited is about three fe^
in height, and the layers are sometimes so thin that
fifty may be counted in the thickness of an inch*
Some of them consist of pure quartz.

Another striking point of analogy between the
stratification of the crystalline formations and that °*
the secondary and tertiary periods, is the alternation, ltt
each, of beds varying greatly in composition, colotfft
and thickness. We observe, for instance, gneiss &
ternating with layers of black hornblende-schist,
with granular quartz or limestone ; and the interchange
of these different strata may be repeated for an inde*

finite number of times. In like manner, mica-sch ist

alternates with chlorite-schist, and with gran
limestone in thin layers.

As we observe in the secondary and tertiary fori* 1 *
ations strata of pure siliceous sand alternating with
micaceous sand and with layers of clay, so in the
"primary" we have beds of pure quartz rock alte**

mica-schist and clay-slate. Aa {n 4 ^ e

nating

with

As in

secondary and tertiary series we meet with limeston
alternating again and again with micaceous or argih a "

Qi- XXVII.] PASSAGE OF GNEISS INTO GRANITE.

363

c eous sand, so we find in the "primary" gneiss and
^ica-schist alternating with pure and impure granular

estones.

Passage of gneiss into granite. — But if we attribute
e stratification of gneiss, mica-schist, and other as-
sociated rocks, to sedimentary deposition from a fluid,
^e encounter this difficulty, — that there is often a
transition from gneiss, a member of the stratified and
therefore sedimentary series, into granite, which, as I
have shown, is of igneous origin. Gneiss is composed
°f the same ingredients as granite, and its texture is
equally crystalline. It sometimes occurs in thick beds,
a *id in these the rock is often quite undistinguishable,
k hand specimens, from granite; yet the lines of
Gratification are still evident. These lines, it is con-
nived, imply deposition from water ; while the passage
x *tto granite would lead us to infer an igneous origin,
fo what manner, then, can these apparently conflicting
v *ews be reconciled ? The Huttonian hypothesis offers,
■*■ think, the only satisfactory solution of this problem.
According to that theory, the materials of gneiss were
°Hginally deposited from water in the usual form of
queous strata; but these strata were subsequently
^tered by subterranean heat, so as to assume a new
texture. The reader will be in some degree prepared,
ty what has been stated in the preceding pages, to
c °nclude, that when voluminous masses of melted and
^candescent rock, accompanied by intensely heated
§ases under great pressure, have been for ages in con-
tact with sedimentary deposits, they may produce great
iterations in their texture; and this alteration may
a dmit of every intermediate gradation between that
^suiting from perfect fusion and the slightest modifi
°ation which heat can produce.

R 2

364<

ALTERATIONS IN STRATA PRODUCED [Book IV

Some light has been thrown on the changes which
stratified masses may undergo subsequently to their
original deposition by direct experiment on the fusion
of rocks in the laboratory; and still more by observ-
ations on strata in contact with igneous veins and dikes*
In studying the latter class of phenomena, we have
the advantage of examining the condition of the same
continuous rock at some distance from the dike, where
it has escaped the influence of heat, and its state where
it has been near to, or in contact with, the fused mass-
The changes thus exhibited may be regarded as the
results of a series of experiments, made by nature on
greater scale than we can imitate, and under every
variety of condition, in respect to the mineral ingred**
ents acted upon, the intensity of heat or pressure, a n(J
the celerity or slowness of the cooling process*

Strata altered by volcanic dikes

Newydd<

One of the most interesting examples of alteration in
the proximity of a volcanic dike occurs near Pl aSS
Newydd, in Anglesea, described by Professor Henslo^'
The dike is 134 feet wide, and consists of a rock whie* 1

is a compound of

(dole

authors). Strata of shale and argillaceous limestone?
through which it cuts perpendicularly, are altered to a
distance of thirty, or even, in some places, to thirty - "
five feet from the edge of the dike. The shale, as 1
approaches the basalt, becomes gradually more coin"
pact, and is most indurated where nearest the junction*
Here it loses part of its schistose structure, but tn
separation into parallel layers is still discernible. *■
several places the shale is converted into hard porce *
lanous jasper. In the most hardened part of tn
mass the fossil shells, principally Productce, are near y
obliterated ; yet even here their impressions may * re

°k. XXVIL]

BY.VOLCANIC DIKES.

365

quently be traced. The argillaceous limestone under-
goes analogous mutations, losing its earthy texture as
xt approaches the dike, and becoming granular and
crystalline. But the most extraordinary phenomenon
ls the appearance in the shale of numerous crystals of
^nalcime and garnet, which are distinctly confined to
those portions of the rock affected by the dike.* Gar-
gets have been observed, under very analogous cir-
cumstances, in High Teesdale, by Professor Sedgwick,
w here they also occur in shale and limestone, altered
by a basaltic dike. This discovery is most interesting,
because garnets often abound in mica-schist ; and we
s ee in the instance above cited that they did not pre-
v iously exist in the shale and limestone, but have
evidently been produced by heat or heated gases in
r ocks in which the marks of stratification have not
been effaced.

Stirling Castle. — To select another example of
iteration by dikes : the fock of Stirling Castle is a
calcareous sandstone, fractured and forcibly displaced
by a mass of green-stone, which has evidently invaded
4 be strata in a melted state. The sandstone has been

lr *durated, and has assumed a texture approaching to
bornstone near the junction. So also in Arthur's Seat
a *id Salisbury Craig, near Edinburgh, a sandstone is
s een to come in contact with green-stone, and to be
converted into a jaspideous rock.-j-

Antrim. — In several parts of the county of Antrim,
111 the north of Ireland, chalk with flints is traversed
by basaltic dikes. The chalk is there converted into
§ r anular marble near the basalt, the change sometimes

* Trans, of Cambridge Phil. Soc, vol. i. p. 406.
t IUust. of Hutt. Theory, §§ 253. and 261. X>r. MacCulloch,
Ge ol. Trans., First Series, voi. ii. p. 305.

R 3

* M

: -

366

ALTERATIONS IN STRATA PRODUCED

[Book

IV.

■

extending eight or ten feet from the wall of the dike?
being greatest near the point of contact, and thence
r'adually decreasing till it becomes evanescent. " The
extreme effect," says Dr. Berger, " presents a dar*
brown crystalline limestone, the crystals running in
flakes as large as those of coarse primitive limestone ;
the next state is saccharine, then fine-grained # n "
arenaceous ; a compact variety, having a porcellanoU 3
aspect and a blueish-grey colour, succeeds ; this, to*
wards the outer edge, becomes yellowish white and #'
sensibly graduates into the unaltered chalk. The fli nts
in the altered chalk usually assume a grey yellowish
colour." * All traces of organic remains are effaced ^
that part of the limestone which is most crystalline.

As the carbonic acid has not been expelled, in thi s
instance, from that part of the rock which must b 6
supposed to have been melted, the change probaW

took place under considerable pressure ; for Sir Ja& eS
Hall proved, that, under ordinary circumstances, jt

would require the weight of about 1700 feet of $&'
water, which would be equivalent to the pressure of a
column of liquid lava about 600 feet high, to preve* 1
this acid from being given off. The experiments °
Faraday have recently shown that, if carbonate of H 1 ** 6
be perfectly dry, it may be melted under a very slig* 1
pressure, without the carbonic acid assuming a g aS *
eous form ; but it is probable that in the earth's eras
calcareous rocks are rarely, if ever, entirely free ft* 0111

moisture.

Another of the dikes of the north-east of Irelan

has converted a mass of red sandstone into hornstone.f

ha*

By another, the slate-clay of the coal-measures

* Dr. Berger, Geol. Trans., First Series, vol. iii. p. 172.
f Rev. W. Conybeare, Geol. Trans., First Series, vol.iii* p-2°

£h. XXVII.]

BY VOLCANIC DIKES.

367

been indurated, and has assumed the character of flinty
slate * ; and in another place the slate clay of the lias
has been changed into flinty slate, which still retains

numerous impressions of ammonites.f One of the
green-stone dikes of the same country passes through
a bed of coal, which it reduces to a cinder for the space
of nine feet on each side. % Yet there are places in
the north of Ireland, where the chalk is scarcely, if at
all, altered by the contact of basaltic dikes, and a
similar phenomenon is not unfrequent in other districts,
at the junction of trap with different kinds of strata.
This great inequality in the effects of the igneous rocks
*nay often arise from an original difference in their
temperature and in that of the entangled gases, such
as is ascertained to prevail in different lavas, or in the
same lava near its source, and at a distance from it.
The power also of the invaded rocks to conduct heat
may vary according to their composition, structure,
and the fractures which they may have experienced,
and, perhaps, as I shall hint in the sequel, the quantity
of steam or hot water they contain. It should also be
borne in mind that in some cases the melted rock may
begin to cool from the first; whereas, in other cases,
although parting constantly with its heat, it may receive
fresh accessions of caloric from below.

The secondary sandstones in Sky are converted into
solid quartz in several places where they come in con-
tact with veins or masses of trap ; and a bed of quartz,
says Dr. MacCulloch, has been found near a mass of
trap, among the coal strata of Fife, which was in all

* Rev. W. Conybeare, Geol. Trans., First Series, vol.iii. p. 205.
f Ibid., p. 213. ; and Playfair, IUust. of Hutt. Theory, §253.
t Ibid., p. 206.

R 4

_ *

368

ALTERATIONS OF STRATA

[Book IV'

probability a stratum of ordinary sandstone subse-
quently indurated by the action of heat.*

°f

Having

selected these from innumerable examples of changes
produced by volcanic dikes, we may next consider
those caused by the contiguity of plutonic rocks. To
some of these I have already adverted, when speaking
of granite veins, and endeavouring to establish the
igneous origin of granite. It was stated that the main
body of the Cornish granite sends forth veins through
the killas of that country f, — a coarse argillaceous
schist, which is converted into hornblende- schist near
the contact with the veins. These appearances are
well seen at the junction of the granite and killas in
St. Michael's Mount, a small island nearly 300 fee*
high, situated in the bay, at a distance of about three
miles from Penzance.,

The granite, says Mr. De la Beche, of Dartmoor?
in Devonshire, has intruded itself into the greywackfe
twisting and contorting the strata, and sending vein*
into them. Hence some of the slate rocks have be-
come " micaceous, others more indurated, and with
the characters of mica-slate and gneiss, while others
again appear converted into a hard-zoned rock strongly

ipregnated with felspar." J

We learn from the investigations of M

that in the eastern Pyrenees there are mountain masses
of granite posterior in date to the lias and chalk of that
district, and that these secondary rocks are greatly
altered in texture, and often charged with iron ore, * n
the neighbourhood of the granite. Thus in the en*

rons of St. Martin, near IS

* Syst. of Geol., vol. i. p. 206.
•f See diagram, Fig. 221.

| Geol. Manual, p. 479

C h. XXVII]

IN CONTACT WITH GRANITE,

369

chalky limestone becomes more crystalline and sac-
c haroid as it approaches the granite, and loses all
traces of the fossils which it previously contained in
abundance. At some points also it becomes dolomitic,
a nd filled with small veins of carbonate of iron, and
s pots of red iron-ore. At Rancie the lias nearest the
granite is not only filled with iron-ore, but charged with
Pyrites, tremolite, garnet, and a new mineral somewhat
allied to felspar, called, from the place in the Pyrenees
*here it occurs, " couzeranite."

In the department of the Hautes Alpes, in France,
fiear Vizille M. Elie de Beaumont traced a black
argillaceous limestone, charged with belemnites, to
within a few yards of a mass of granite. Here the

Fig. 225.

** u *cti<m of granite with Jurassic or oolite strata in the Alps, near Champoleon*

^^estone begins to put on a granular texture, but is
extremely fine-grained. When nearer the junction, it
becomes grey and has a saccharoid structure. In
Mother locality, near Champoleon, a granite com-

r 5

370

ROCKS, HOW ALTERED BY

[Book l v

posed of quartz, black mica, and rose-coloured felspar?
is observed partly to overlie the secondary rocks, pi" '
ducing an alteration which extends for about thirty
feet downwards, diminishing in the beds which H e
farthest from the granite. (See Fig. 225.) In the
altered mass the argillaceous beds are hardened, the
limestone is saccharoid, the grits quartzose, and in the
midst of them is a thin layer of an imperfect granite-
It is also an important circumstance, that near the
point of contact, both the granite and the secondary
rocks become metaliferous, and contain nests and small
veins of blende, galena, iron, and copper pyrites. The
stratified rocks become harder and more crystalline*
but the granite, on the contrary, softer and less per'
fectly crystallized near the junction.*

It will appear from sections in the Alps, described
by MM. Hugi and Studer, that some of the secondary
beds of limestone and slate, which are in a simile
manner overlaid by granite, have been altered into
gneiss and mica-schist.f Some of these altered sedi-
mentary formations are supposed, by M. Elie de Beau-
mont, to be of the age of the lias of England, and
others to be even as modern as the Jurassic or ooH te

formations.

We can scarcely doubt, in these cases, that the hea*
communicated by the granitic mass, accompanied, per-
haps, by gases at a high temperature, have reduced
the contiguous strata to semifusion, and that, on cool-
ing slowly, the rock assumed a crystalline texture.

Watt

* Elie de Beaumont, sur les Montagnes de l'Oisans, # c ' ?
Mem. de la Soc. d'Hist. Nat. de Paris, tome v.

f Hugi, Natur. Historische Alpenreise, Soleure, 1830. Studeft
Westlichen Alpen.

Ch. XXVIL] PERMEATION OF HEAT AND GASES.

371

that a rock need not be perfectly melted in order that
a re-arrangement of its component particles should
take place, and that a more crystalline texture should
ensue.* We may easily suppose, therefore, that all
traces of shells and other organic remains may be de-
stroyed, and that new chemical combinations may
arise, without the mass being so fused as that the
Hnes of stratification should be wholly obliterated.

In allusion to the passage from granite to gneiss,
above described f, Dr. MacCulloch remarks, that, " in
numerous parts of Scotland, where the leading masses
of gneiss are schistose, evenly stratified, and scarcely
ever traversed by granite veins, they become contorted
and irregular as they approach the granite ; assuming
also the granitic character, and becoming intersected
by veins, numerous in proportion to the vicinity of the
. The conclusion," he adds, " is obvious ; the
fluid granite has invaded the aqueous stratum as far as
its influence could reach, and thus far has filled it with
veins, disturbed its regularity, and generated in it a
new mineral character, often absolutely confounded
with its own. And if the more remote beds, and
those alternating with other rocks, are not thus af-
fected, it is not only that it has acted less on those ;
but that, if it had equally affected them, they never
could have existed, or would have been all granitic

and venous gneiss." J

It should, however, be understood, that the alter-
ations caused by volcanic dikes, granite veins, and
even large masses of granite, can only afford us some
analogy to those which have given rise to the meta-

*nas

;

* Phil. Trans., 1804.

t Syst. of Geol., vol.ii. p. 145.

R 6

See p. 364

Ifl I

372

ROCKS, HOW ALTERED BY

[Book IV.

morphic structure ; for, according to the views ex-
plained in the second book (chaps. 18 and 19.), vol-
canic heat itself may be derived from chemical and
electrical action pervading large portions of the earth's
crust. This action, which, when most intense, may
reduce the elements of rocks to fusion, and give rise

to the most perfect granitic structure, may perhaps?

when less energetic, give rise to a crystalline texture
without destroying stratification.

As to the degree of heat required to superinduce
such changes, it must, in the present state of science?
be matter of conjecture ; but some geologists object to
the metamorphic theory, on the ground that rocks are
extremely bad conductors of heat. Now it is worthy
of consideration, how far heat, instead of being con-
ducted through the solid parts of rocks, may be
carried by heated gases through their pores ; for we
have seen that volcanic eruptions are attended by the
evolution of steam and other gases, which rush out i* 1
enormous volume, and at a high temperature, for days?
weeks, or years continuously, and which are given off
by lava even after it has begun to assume a solid form-
These aeriform fluids, if unable to force their way
into the atmosphere, may, nevertheless,, when brought
into contact with rocks, pass through their pores*
According to the experiments of Henry, water, under
an hydrostatic pressure of ninety-six feet, will absorb
three times as much carbonic acid gas as it can under
the ordinary pressure of the atmosphere. Although
this increased power of absorption would be dimi-
nished, in consequence of the higher temperature
found to exist as we descend in the earth, y et
Professor BischofF has shown that the heat by n°
means augments in such a proportion as to counteract

•

Ch . XXVII.] PERMEATION OF HEAT AND GASES.

373

the effect of augmented pressure.* There are other
gases, as well as the carbonic acid, which water
^sorbs, and more rapidly in proportion to the amount
°f pressure. Now even the most compact rocks may
he regarded, before they have been exposed to the air
and dried, in the light of sponges filled with water ;
ai *d it is conceivable that heated gases brought into
contact with them, at great depths, may be absorbed
r eadily, and transfused through their pores. Although
the gaseous matter first absorbed would soon be con-
densed, and part with its heat, yet the continued
arrival of fresh supplies . from below, might, in the
course of ages, cause the temperature of the water,
a nd with it that of the containing rock, to be mate-
rially raised.
M. Fournet, in his description of the metaliferous

gneiss near Clermont, in Auvergne, states that all the
minute fissures of the rock are quite saturated with
*ree carbonic acid gas, which rises plentifully from
the soil there and in many parts of the surrounding
country. The various elements of the gneiss, with
the exception of the quartz, are all softened ; and new
combinations of the acid, with lime, iron, and man-
ganese, are continually in progress.f

Another illustration of the power of subterranean
gases is afforded by the stufas of St. Calogero, situated
ir * the largest of the Lipari Islands. Here, according
to the description lately published by Hoffmann, hori-
zontal strata of tuff, extending for four miles along
the coast, and forming cliffs more than 200 feet high,
have been discoloured in various places, and strangely
altered by the " all-penetrating vapours/? Dark clays

Poggendorf s Annalen, No. XVI. Second Series, vol. iii.

t See Vol. I. p. 331.

-* -'J

■

374

ROCKS, HOW ALTERED BY

[Book IV,

have become yellow, or often snow-white ; or have as-
sumed a chequered and brecciated appearance, being
crossed with ferruginous red stripes. In some places
the fumeroles have been found by analysis to consist
partly of sublimations of oxide of iron ; but it also
appears that veins of calcedony and opal, and others
of fibrous gypsum,
exhalations.*

have resulted from these volcanic

I have before referred to M. Virlet's account of the
corrosion of hard, flinty, and jaspideous rocks near
Corinth, by the prolonged agency of subterranean

ises f ; and to Dr. Daubeny's description of the de-
composition of trachytic rocks in the Solfatara, near
Naples, by sulphuretted hydrogen and muriatic acid

gases. X

Although in all these instances we can only study
the phenomena as exhibited at the surface, it is clear
that the gaseous fluids must have made their way
through the whole thickness of porous or fissured
rocks, which intervene between the subterranean re-
servoirs of gas and the external air. The extent
therefore, of the earth's crust, which the vapours have
permeated and are now permeating, may be thousands
of fathoms in thickness, and their heating and modi-
fying influence may be spread throughout the whole ot
this solid mass.

The study of metaliferous veins, also, especially
those which are admitted to be fissures filled from
below, is calculated to throw light on the manner i* 1
which heated vapours and aqueous solutions may fi n( *

* Hoffmann's Liparischen Inseln, p. 38. Leipzig, 1832.
| See Vol. III. p. 203. ; and Bulletin de la Soc. Geol
France, torn. ii. p. 330.

i See Vol. II. p. 90. ; and Daubeny's Volcanos, p. 167.

Ch. XXVII.] PERMEATION OF HEAT AND GASES.

375

their way up through the interstices of rocks, raising
their temperature, and sometimes transfusing into
them new mineral substances. A great number of these
fissures have evidently been filled in the first instance
with rubbish, resulting from fragments of the adjoining
rocks ; and through this rubbish various siliceous, cal-
careous, and metallic vapours or solutions appear to
have risen, causing precipitates of quartz, hornstone,
calcareous spar, lead, zinc, and other metals, often
perfectly distinct in their composition from any of the
elements of the rocks which form the walls of such
fissures. Proofs are not wanting that these rents have
been caused and filled at different epochs. Thus, for
example, some of the silver and cobalt veins in Bohemia
appear, from the observations of Mayer and Fournet,
to be of the age of the chalk * , while other metaliferous
veins, in the same district, were contemporaneous with
a tertiary basalt.f M. Necker has also shown that a
relation exists between the position of numerous me-
tallic veins in various countries and subjacent masses
of plutonic rock ; so that the emanations rising from
such igneous masses may, in many instances, have
given rise to the more crystalline substances, whether
metallic or not, which constitute the contents of the
veins.

If, after more fully reflecting upon those various
causes of change in the composition and structure of
rocks, which have only been glanced at in the above
sketch, the reader conceives the possibility of a very
great amount of alteration being induced in the course
of time, he may be prepared to conjecture that gneiss
and mica-schist may be nothing more than altered mi-

* D'Aubuisson, Traite de G£og., torn. iii. p. 497.
f Ibid., p. 508.

376

THE GRANITIC SCHISTS

[Book IV.

caceous and argillaceous sandstones, and^hat granular
quartz may have been derived from siliceous sandstone?
and compact quartz from the same materials. Clay-
slate may be altered shale, and shale appears to be clay
which has been subjected to great pressure. Granule
marble has probably originated in the form of ordinary
limestone, having in many instances been replete with
shells and corals now obliterated, while calcareous
sands and marls have been changed into impure crys-

■

talline limestones.

" Hornblende-schist," says Dr. MacCulloch, " may
at first have been mere clay ; for clay or shale is found
altered by trap into Lydian stone, a substance differing
from hornblende-schist almost solely in compactness
and uniformity of texture."* " In Shetland," remarks
the same author, " argillaceous-schist (or clay-slate)?
when in contact with granite, is sometimes converted
into hornblende-schist, the schist becoming first sili-
ceous, and ultimately, at the contact, hornblende-

sehist."f

Associated with the rocks termed primary, we meet
with anthracite, just as we find beds of coal in sedi-
mentary formations ; and we know that, in the vicinity
of some trap dikes, coal is converted into anthracite.

This theory, if confirmed by observation and ex-
periment, may enable us to account for the high
position in the series usually held by clay-slate r e "
latively to hornblende-schist, as also to gneiss and mica*
schist, which so commonly alternate with hornblende-
schist ; for we must suppose the heat which alters the
strata to proceed, in almost all cases, from below up-
wards, and to act with greatest intensity on the inferior
strata. If, therefore, several sets of argillaceous strata

* Syst. of Geol., vol. i. p. 210.

f Ibid., p. 211

Ch. XXVII.]

MAY BE ALTERED STRATA.

377

or shales be superimposed upon each other in a vertical
series of beds in the same district, the lowest of these
^ill be converted into hornblende-schist, while the up-
permost may continue in the condition of clay-slate.

It has been objected that the chemical composition
of the secondary strata differs essentially from that of
the crystalline schists into which they are supposed to
be convertible.* The "primary" schists* it is said,
Usually contain a considerable proportion of potash or
of soda, which the secondary clays, shales and slates do
not, these last being the result of the decomposition of
felspathic rocks, from which the alkaline matter has
been abstracted during the process of decomposition.
But this reasoning proceeds on insufficient and ap-
parently mistaken data ; for a large portion of what is

Usually called clay, marl, shale, and slate does actually
contain a certain and often a considerable proportion of
alkali ; so that it is difficult in many countries to obtain
clay or shale sufficiently free from alkaline ingredients
to allow of their being burnt into bricks or used for
pottery.

Thus the argillaceous shales, as they are called, and
slates of the old red-sandstone, in Forfarshire and other
parts of Scotland, are so much charged with alkali,
derived from triturated felspar, that, instead of harden-
*ng when exposed to fire, they melt readily into a
glass. They contain no lime, but appear to consist of
extremely minute grains of the various ingredients of
granite, which are distinctly visible in the coarser-
grained varieties, and in almost all the interposed
sandstones. These laminated clays, marls, and shales
**%ht certainly, if crystallized, resemble in composition
***any of the primary strata.

* Dr. Boase, Primary Geology, p. 319.

■ I

378

ALTERED STRATA.

[Book

IV.

Another objection to the metamorphic theory has
been derived from the alternation of highly crystalline
strata with others having a less crystalline texture*
The heat, it is said, in its ascent from below must have
traversed the less altered schists before it reached
a higher and more crystalline bed. In answer t°
this, it may be observed, that if a number of strata
differing greatly in composition from each other be
subjected to equal quantities of heat, there is every
probability that some will be&more fusible than others*
Some, for example, will contain soda, potash, lime, o r
some other ingredient capable of acting as a flux ; while
others may be destitute of the same elements, and $°
refractory as to be very slightly affected by a degree
of heat capable of reducing others to semi-fusion. ^° r
should it be forgotten that, as a general rule, the le sS
crystalline rocks do really occur in the upper, and the
more crystalline in the lower part of each metamorph 1

series.

To some it appears a phenomenon very difficult ° l
explanation, that detached masses of granite, and eve**
layers of it, should often occur in the midst of strata
near their contact with granite. This appearance °
isolation is usually deceptive, arising from the inter'
section in a vertical precipice of tortuous veins °
granite, as Professor Henslow has shown to be tn e
case in several places in the cliffs of Anglesea.* I ^^
also remark, that if unaltered sedimentary strata con-
tained here and there layers or nests of the ingredients
of granite, the rest of the mass consisting of differed
materials, and if the temperature of the whole has
been sufficiently raised by plutonic action, the resu

* Camb. Trans., voL i.

's ^

Ch. XXVII.]

HYPOGENE STRATA.

379

might be, that nodules and threads of granite might
be formed in certain spots only.

The term " Hypogene " proposed instead of Pri-
mary. — It will appear from the reasoning explained in
this and the preceding chapter, that the popular no-
menclature of Geology, in reference to the rocks called
u primary," is not only imperfect, but in a great degree
founded on a false theory ; inasmuch as some granites
and granitic schists are of origin posterior to many
secondary rocks. In other words, some primary form-
ations can already be shown to be newer than many
secondary groups — a manifest contradiction in terms.

Yet granite and gneiss, and the families of stratified
and unstratified rocks connected with each of them,
belong to one great natural division of mineral masses
having certain characters in common ; and it is there-
fore convenient that the class to which they belong

should receive some common name — a name which
must not be of chronological import, and must express,
on the one hand, some peculiarity equally attributable
to granite and gneiss (to the plutonic as well as the
altered rocks), and which, on the other, must have refer-
ence to characters in which those rocks differ, both
from the volcanic and from the unaltered sedimentary
strata. I propose the term " hypogene " for this pur-
pose^ derived from vm 9 subter, and ywopai, nascor ; a
Word implying the theory that granite and gneiss are
both nether-formed rocks, or rocks which have not as-
sumed their present form and structure at the surface.
It is true that gneiss and all stratified rocks must have
been deposited originally at the surface, or on that part
of the surface of the globe which is covered by water ;

but, according to the views explained in this and the
foregoing chapter, they could never have acquired

m ^.

; ; :

i ■

•

380

METAMORPHIC STRATA

[Book

their crystalline texture, unless acted upon by heat and
chemical forces under pressure in those regions, and
under those circumstances where the plutonic rocks
are generated.

The term " Metamorphic " proposed for stratified

We mav divide the hypogene rocks, then

primary.

into the unstratified, or plutonic, and the altered stra-
tified. For these last the term " metamorphic " (from
pera, trans, pogcpYj, forma,) may be used. The la st *
mentioned name need not, however, be often resorted
to, because we may speak of hypogene strata, hyp '
gene limestone, hypogene schist ; and this appellate
will suffice to distinguish the formations so designated

table

from the plutonic rocks. By referring to the

(No. II. p. 395.), the reader will see the chronologic 1

relation which I conceive the two classes of hypoge ne

rocks to bear to the strata of different ages.

No order of succession in hypogene formations

When we regard the tertiary and secondary forifl a
tions simply as mineral masses uncharacterized W

organic remains, we perceive an indefinite series

beds of limestone, clay, marl, siliceous sand, sandstone
coal, and other materials, alternating again and ag& irl
without any fixed or determinate order of positio* 1 '
The same may be said of the hypogene formations 5
for in these a similar want of arrangement is manifest
if we compare those occurring in different countries-
Gneiss, mica-schist, hornblende-schist, quartz-rock, hy-
pogene limestone, and the rest, have no invariable ordei
of superposition, although, for reasons above explained?
clay-slate must usually hold a superior position rela*

tively to hornblende-schist.

I do not deny that, in a particular mountain-chaifl?

a chronological succession of hypogene formations vndj

Ch. XXVII.]

METAMORPHIC STRATA.

381

be recognized, for the same reason that in a country
of limited extent there is an order of position in the

secondary and tertiary rocks, limestone predominating
in one part of the series, clay in another, siliceous sand
in a third, and so of other compounds. It is probable
that a similar prevalence of a regular order of arrange-
ment in the hypogene series throughout certain dis-
tricts led the earlier geologists into a belief that they
should be able to fix a definite order of succession for
the various members of this great class throughout

the world.

That expectation has certainly not been realized;
yet was it more reasonable than the doctrine of the
Universality of particular kinds of rock which were
admitted to be of sedimentary origin; for there is
undoubtedly a remarkable identity in the mineral cha-
racter of the hypogene formations, both stratified and
Unstratified, in all countries ; although the notion of a
Uniform order of succession in the different groups

Uiust be abandoned.

The student may, perhaps, object to the views above
given of the relation of the sedimentary and metamor-
phic rocks, on the ground that there is frequently,
indeed usually, an abrupt passage from one to the other.
This phenomenon, however, admits of the same expla-
nation as the fact that the beds of lakes and seas are
Uow frequently composed of hypogene rocks. In these
localities the hypogene formations have been brought
Up near to the surface, and laid bare by denudation.
New sedimentary strata are thrown down upon them,
tod in this manner the two classes of rocks, the aque-
ous and the hypogene, come into immediate contact,
without any gradation from one to the other. As we

suppose the plutonic and metamorphic rocks to have

'I ill

382

METAMORPHIC STRATA.

[Book

IV,

■

been uplifted at all periods in the earth's history, so as
to have formed the bottom of the ocean and of lakes,
by the same operations which have carried up marine
strata to the summits of lofty mountains, we must
suppose the juxtaposition of the two great orders ot
rocks, now alluded to, to have been a necessary result
of all former revolutions of the globe.

But occasionally a transition is observable from strata
containing shells, and displaying an evident mechanical
structure, to others which are partially altered ; and
from these again we sometimes pass insensibly into the
hypogene series. Some of the argillaceous schists m
Cornwall are of this description, being undistinguish-
able from the hypogene schists of many countries, and
yet exhibiting, in a few spots, faint traces of organic
remains. In parts of Germany, also, there are schist
which, from their chemical condition, must be called
metamorphic ; yet which are interstratified with grey*
wacke, a rock probably modified by heat, but whfc* 1
contains casts of shells, and often displays unequivocal
marks of being an aggregate of fragments of pre-exis t-
ing rocks.

the

Welsh

described by Professor Sedgwick. * They are meta-
morphic slates alternating with a few mechanical and
fossiliferous beds. If it be asked by what characters
we can draw the line and determine where the nieta

morphic series ends, and the sedimentary begins,
reply that, if this be difficult or impossible, it only
strengthens the argument adduced in the preceding
part of this chapter; for, according to the theory
proposed, we must expect to find strata in every inter-

* See p. 355.

(

Ch. XXVII.]

AGE OF HYPOGENE STRATA.

383

mediate condition between the most and the least

altered.

Had Werner's term "transition" been restricted
exclusively to certain peculiarities of mineral struc-
ture, and never connected with the presence of par-
ticular species of fossils, in consequence of which it
soon acquired a chronological import, that term might
have been conveniently retained to designate an
intermediate condition of strata when they exhibit the
characters of rocks of the metamorphic series with

occasional traces of a mechanical structure and organic
remains.

Some geologists, who shrink from the theory that
all the hypogene strata, beautifully compact and crys-
talline as they are, have once been in the state of
ordinary mud, clay, marl, sand, gravel, and limestone,
such as are now forming beneath the waters, resort, in
their desire to escape from such conclusions, to the hy-
pothesis, that chemical causes once acted with intense
energy, and that by their influence purely crystalline
strata were precipitated ; a theory which to me appears
as mysterious and unphilosophical as the doctrine of a
plastic virtue/' introduced by the earlier writers to
explain the origin of fossil- shells and bones.

Relative age of the visible hypogene rocks. — It was
stated, at the close of the last chapter, that a great
Portion of the plutonic rocks now visible are of higher
antiquity than the oldest secondary strata; the same
^ay be said of the stratified hypogene formations,
Much are therefore entitled to the appellation of pri-
mary, in the strict sense of the word, as anterior in age
to the greywacke, or oldest known fossiliferous group,
^ut we can, in some instances, demonstrate that there
a *e granites of posterior origin to certain secondary

384

RELATIVE AGE OF

[Book IV.

strata? and that secondary strata have been converted
into the metamorphic. Examples of such phenomena,
are rare, and their rarity is quite consistent with the
theory, that the hypogene formations, both stratified
and unstratified, may have been always generated
in nearly equal quantities during periods of equal

duration.

I conceive that the granite and gneiss of perio
more recent than the carboniferous and greywacke
formations are still, for the most part, concealed; and

can

those portions which are visible can rarely be shown
by geological evidence, to have originated during
secondary periods. It is very possible, for example
that considerable tracts of hypogene strata in the
Alps may be altered oolite, altered lias, or altered
secondary rocks inferior to the lias ; but we
scarcely ever hope to substantiate the fact, because
whenever the change of texture is complete, no charac
ters remain to afford us any insight into the probable

age of the mass. Where granite happens to have in-
truded itself in such a manner as partially to overlie a
•mass of lias or other strata, as in the case before alluded

to (Fig. 225., p. 369.), we may prove that fossilifero^ s
strata have been converted into gneiss, mica-schist
clay-slate, or granular marble ; but if the action of the
heat upon the strata had been more intense, these
inferences could not have been drawn; and it mign
then have been supposed that no alpine hypogen
strata were newer than the oldest secondary rocks.

Considerable difficulty and misapprehension,, in re-
gard to the antiquity of the metamorphic rocks, may
arise from the circumstance of their having been de-
posited at one period, and having assumed their crys-

talline texture at another. Thus, for example, if an

Ch. XXVIL]

HYPOGENE STRATA.

385

Eocene granite should invade the lias, and superinduce
a hypogene structure, to what period shall we refer the
altered strata ? Shall we say that they are metamorphic
rocks of the Eocene or Liassic eras? They assumed
their stratified form when the animals and plants of
the lias flourished; they have become metamorphic
during the Eocene period. It would be preferable in
such instances, I think, to consider them as hypogene
strata of the Eocene period, or of that in which they
were altered ; yet it would rarely be possible to esta-
blish their true age. For this purpose we ought to
know the granite, to which the change of texture was
due, to be newer than the lias which it penetrated •
but there would rarely be any data to show that this
granite might not have been injected at the close of
the Liassic period, or at some much later era.

The metamorphic rocks must in all cases be the
oldest, that is to say, they must lie at the bottom of
each series of superimposed strata ; but the hypogene
strata of one country may be, and frequently are, of a
very different age from those of another. The greater
part, however, of the visible hypogene rocks are, pro-
bably, more ancient than the oldest fossiliferous form-
ations. In the latter we frequently discover pebbles
of hypogene rocks, namely, granite, gneiss, mica-
schist, and clay-slate; and the carboniferous rocks
often rest upon the hypogene, without exhibiting any
marks of change at the junction. According to the
views before explained of the operations of earth-
quakes, we ought not to expect plutonic and metamor-
phic rocks of the more modern eras to have reached
the surface generally ; for we must suppose many
geological periods to elapse before a mass, which has
assumed its particular form far below the level of the

VOL. IV.

386

RELATIVE AGE OF

[Book

IV.

sea can have been upraised and laid open to view
above that level. Beds containing marine shells some-
times appear in the principal mountain-chains, at the
height of two or three miles above the sea ; but they
always belong to formations of considerable antiquity •
still more, then, should we be prepared to find the
hypogene rocks now in sight to be of high relative
antiquity, since, before they could be brought up to
view, they must probably have risen from a site tox
inferior to the bottom of the ocean.

The cause of the great age of the plutonic and
metamorphic rocks, now in sight, may be elucidated
by a familiar illustration. Suppose two months to be
the usual time required for passing from some tropic* 1
country to our island, and that an annual importation
takes place of a certain species of insect which can be
reared only in the climate of that equatorial country
and the ordinary term of whose life is two months*
It is evident that no living individuals of that specif
could ever be seen in England except in extreme o\
age. The young may come annually into the world i* 1
great numbers ; but, in order to see them, we m uS
travel to lands near the equator.

In like manner, if the hypogene rocks can originate
only at great depths in the regions of subterranean
heat, and if it requires many geological epochs to raise
them to the surface, they must be very ancient befo^
they make their appearance in the superficial parts o
the earth's crust. They may still be forming in every
century, and they may have been produced in equ a
quantities during each successive geological period o
equal duration ; but in order to see them in a nascen
state, slowly consolidating from a state of fusion, °

Ch. XXVII.]

CM
CM

.J?

HYPOGENE STRATA.

c/5

1/2

CJ .
r;

to
c

r - *

c/3
O

0>
rB

c
o

rB
C/3

fcJO

387

5- ^

(/I

r-i

b
o

• ***
5-

rji Cft CM

O S

g o

S "3

*-.

C-

Ph w h K

c a

s 2

388

RELATIVE AGE OF

[Book IV

■

semi-fusion, it would be necessary to descend into the
" fuelled entrails" of the earth.

In the accompanying diagram, Fig. 226., an attempt
is made to show the inverted order in which the sedi-
mentary and plutonic formations may occur in the
earth's crust ; subterposition in the plutonic, like super-
position in the sedimentary rocks, being for the most
part characteristic of a newer age.

The oldest plutonic rock, No. L, supposed to have
consolidated from a state of fusion before any of the
fossiliferous rocks now on the surface were deposited,
has been upheaved at successive periods until it has
become exposed to view in a mountain-chain. This

protrusion of No. I. has been caused by the igneous
agency which produced the new plutonic rocks Nos.II-
III. and IV. Part of the metamorphic rocks No. J.
have also been raised to the surface by the same gradual
process. It will be observed that the Recent strata

No. 4. and the Recent plutonic rock No. IV. are the
most remote from each other in position, although of
contemporaneous date. According to this hypothesis
the convulsions of many periods will be required be-
fore Recent granite will be upraised so as to form the
highest ridges and central axes of mountain-chains.
During that time the Recent strata No. 4. might be
covered by a great many newer sedimentary form-
ations.

As the progress of decay and reproduction by
aqueous agency is incessant on the surface of the
continents, and in the bed of the ocean, while the
hypogene rocks are generated below, or are rising
gradually from the volcanic foci, there must ever be
a remodelling of the earth's surface in the time inter-
mediate between the origin of each set of plutonic

Ch. XXVII.]

HYPO GENE STRATA.

389

and metamorphic rocks, and the protrusion of the same
rocks into the atmosphere or the ocean. Suppose
the principal source of the Etnean lavas to lie at
the depth of ten miles, we may easily conceive that
before they can be uplifted to the day several distinct
series of earthquakes must occur, and between each of
these there might usually be one or many periods of
tranquillity. The time required for so great a develop-
ment of subterranean movements might well be pro-
tracted until the deposition of a series of sedimentary
rocks, equal in extent to all our secondary and tertiary
formations, had taken place.

The relative age, therefore, of the visible plutonicv;
and metamorphic rocks, as compared to the unaltered//
sedimentary strata, must always be determined by tliefjl
relations of two forces — the power which uplifts the
hypogene rocks, and that aqueous agency which de- /
grades and renovates the earth's surface ; or, in other /
words, the relative age must depend on the quantity
of aqueous action which takes place between two W

periods

that during which the heated and melted

rocks are cooled and consolidated in the nether regions, ]
and that of their emergence at the earth's surface.

Volume of hypogene rocks supposed to have been
formed since the Eocene period. — If we were to indulge
in speculations on the probable quantity of hypogene
formations, both stratified and unstratified, which may
have been formed beneath Europe and the European
seas since the commencement of the Eocene period, it
might be conjectured that the mass has equalled, if
not exceeded in volume, the entire European con-
tinent. The grounds of this opinion will be under-
stood by reference to what I have said of the causes
which may have upheaved part of Sicily to its present

s 3

390

RELATIVE AGE OF

[Book IV

height above the level of the sea since the beginning
of the Newer Pliocene period.* If the theory which,
in that instance, attributes the disturbance and up-
heavings of the superficial strata to the action of sub-
terranean heat be deemed admissible, the same argu-
ment will apply with no less force to every other
district, elevated or depressed, since the commence-
ment of the tertiary period.

But the remarks on the map of Europe, in the first
book, have shown, that the conversion of sea into land,
since the Eocene period, embraces an area equal to
the greater part of Europe ; and that even those tracts
which had in part emerged before the Eocene era,
such as the Alps, Apennines, and other mountain-
chains, have risen to the additional altitude of from
one thousand to four thousand feet since that era- I
have also suggested the probability of a great amount
of subsidence, and the conversion of considerable
portions of European land into sea, during the same

period,

changes which may be supposed to arise

from the influence of subterranean heat.

From these premises we may conclude, that the
liquefaction and alteration of rocks, by the operation
of volcanic heat at successive periods, has extended
over a subterranean space, equal at least in area to the
present European continent, and has often pervaded a
portion of the earth's crust four thousand feet or more
in thickness.

The principal effect of these volcanic operations in
the nether regions, during the tertiary periods, or
since the existing species began to flourish, has been
to heave up to the surface hypogene formations of an
age anterior to the carboniferous. The repetition of

* See Vol. III. p. 437.

Ch. XXVII.]

HYPOGENE STRATA.

391

another series of movements, of equal violence, might
upraise the plutonic and metamorphic rocks of many
of the secondary periods ; and if the same force should
still continue to act, the next convulsions might bring
up the tertiary and recent hypogene rocks ; by which
time we may imagine that nearly all the sedimentary
strata now in sight would either have been destroyed
by the action of water, or have assumed the meta-
morphic structure, or would have been melted down
into plutonic and volcanic rocks.

At the end of this chapter will be found a table of
the chronological relations of the principal divisions of
rocks according to the views above set forth. The
sketch is confessedly imperfect ; but it will elucidate
the theory above suggested, of the connection which
may exist between the hypogene rocks of different
periods, and the alluvial, volcanic, and sedimentary
formations.

mere

Concluding Remarks.

In the history of the progress of geology, it has
been stated that the opinion originally promulgated
by Hutton, " that the strata called primitive were

altered sedimentary rocks," was vehemently
opposed for a time, on the ground of its supposed
tendency to promote a belief in the past eternity of
our planet. * Before that period the absence of animal
and vegetable remains in the so-called primitive
strata had been appealed to, as proving that there
had been an era when the planet was uninhabited by
living beings, and when, as was also inferred, it was

* Vol. I. p. 92.

s 4;

392

CONCLUDING REMARKS.

[Book IV.

uninhabitable, and, therefore, probably in a nascent

state.

The opposite doctrine, that the oldest visible strata
might be the monuments of an antecedent period,
when the animate world was already in existence,
was declared to be equivalent to the assumption that
there never was a beginning to the present order of
things. The unfairness of this charge was clearly
pointed out by Playfair, who observed, « that it was
one thing to declare that we had not yet discovered
the traces of a beginning, and another to deny that the
earth ever had a beginning."

I regret, however, to find that the bearing of my
arguments in the first book has been misunderstood in
a similar manner ; for I have been charged with en-
deavouring to establish the proposition, that « the ex-
isting causes of change have operated with absolute
uniformity from all eternity." *

It is the more necessary to notice this misrepresent-
ation of my views, as it has proceeded from a friendly
critic, whose theoretical opinions coincide in general
with my own ; but who has, in this instance, strangely
misconceived the scope of the argument. With equal
justice might an astronomer be accused of asserting
that the works of creation extended throughout in-
finite space, because he refuses to take for granted
that the remotest stars now seen in the heavens are
on the utmost verge of the material universe. Every
improvement of the telescope has brought thousands
of new worlds into view ; and it would, therefore, be
rash and unphilosophical to imagine that we already
survey the whole extent of the vast scheme, or that

Quarterly Review, No. 86., Oct. 1830, p. 464,

■

Ch. XXVI I.]

CONCLUDING REMARKS.

393

may have commenced at a certain period. It has also
been urged, that, as we admit the creation of man to
have occurred at a comparatively modern epoch — as
we concede the astonishing fact of the first introduc-
tion of a moral and intellectual being — so also we may
conceive the first creation of the planet itself.

I am far from denying the weight of this reasoning
from analogy; but, although it may strengthen our
conviction, that the present system of change has not
gone on from eternity, it cannot warrant us in pre-
suming that we shall be permitted to behold the signs
of the earth's origin, or the evidences of the first
introduction into it of organic beings. We aspire in

• s5

■

it will ever be brought within the sphere of human
observation.

But no argument can be drawn from such premises
in favour of the infinity of the space that has been
filled with worlds ; and if the material universe has
any limits, it then follows that it must occupy a minute
and infinitesimal boint in infinite space*

'acing back the earth's history, we arrive
at the monuments of events which may have happened
millions of ages before our times, and if we still find
no decided evidence of a commencement, vet the
arguments from analogy in support of the probability
of a beginning remain unshaken; and if the past
duration of the earth be finite, then the aggregate of
geological epochs, however numerous, must constitute
a mere moment of the past, a mere infinitesimal por-
tion of eternity. |

It has been argued, that, as the different states of
the earth's surface, and the different species by which
it has been inhabited, have all had their origin, and

many of them their termination, so the entire series

111

I i

394

CONCLUDING ItEMARKS.

[Book IV

vain to assign limits to the works of creation in space?
whether we examine the starry heavens, or that
world of minute animalcules which is revealed to us
by the microscope. We are prepared, therefore, to
find that in time also the confines of the universe lie
beyond the reach of mortal ken. But in whatever
direction we pursue our researches, whether in time
or space, we discover every where the clear proofs of
a Creative Intelligence, and of His foresight, wisdom,

and power.

As geologists, we learn that it is not only the pre-
sent condition of the globe which has been suited to
the accommodation of myriads of living creatures, but
that many former states also have been adapted to the
organization and habits of prior races of beings;: The
disposition of the seas, continents, and islands', and the
climates, have varied ; the species likewise have been

changed ; and yet they have all been so modelled, on
types analogous to those of existing plants and animals?
as to indicate throughout a perfect harmony of design
and unity of purpose. To assume that the evidence
of the beginning or end of so vast a scheme lies within
the reach of our philosophical inquiries, or even of our
speculations, appears to be inconsistent with a just
estimate of the relations which subsist between the
finite powers of man and the attributes of an Infinite
and Eternal Being.

395

'•

TABLE II.

Showing the Relations of the Alluvial, Aqueous, Volcanic, and

Hypogene Formations of different Ages.

Periods.

Formations.

Some of the Localities where
the Formations occur.

f Alluvial

Aqueous

Table I. ^
p. 301.

Volcanic.

L Hypogene.

r Alluvial

Newer
Pliocene.

B.
Table L
p. 301.

Aqueous.
Volcanic.

I Hypogene

a. Marine.

b. Freshwater,

a. Plutonic.

b. Metamor-
phic.

Marine.
Freshwater.

a. Plutonic.

b, Metamor-
phic.

f Beds of existing rivers,
\ &c. book iii. ch. xiv.
Coral reefs of the Pacific,

book iii. ch. xviii.
Bed of Lake Superior,
&c, book ii. ch. iv.
f Etna, Vesuvius, book ii.
\ chs. x« xi. xii.
Concealed ; foci of active
volcanos, book iv. ch.

xxvi.
Concealed ; around the
foci of active volcanos,
book iv. ch. xxvii.

{Gravel covering the
Newer Pliocene strata
of Sicily.
Val di Noto, Sicily.
Colle, in Tuscany.
Val di Noto, Sicily.
Concealed; foci of Newer
Pliocene volcanos —
underneath the Val di

Noto,Vol.III.p.437.,
and book iv. ch. xxvii.
Concealed ; near the foci
of Newer Pliocene vol-
canos — underneath the
Val di Noto, Vol. III.
p. 437., and book iv.
ch, xxvii.

S 6

396

CHRONOLOGICAL RELATIONS

TABLE II. — continued.

o
«

Periods.

Formations.

f Alluvial,

Older

Pliocene.
C.

Table I.

p. 301.

Aqueous.

Volcanic.

^Hypogene.

f Alluvial.

Miocene.
D.

Table I.
p. 301.

Aqueous.

Volcanic.

LHypogene.

Alluvial

4.
Eocene.

E.
Table I.
p. 302.

Aqueous.

Volcanic.

Hypogene,

Some of the Localities where
the Formations occur.

Marine.

Freshwater.

Plutonic.

Norfolk? Vol. IV. p. 78.
Subapennine formations,

Vol. IV. p. 49.
Near Sienna, Vol. IV.

p. 55.

Tuscany, Vol. IV. p. 54.
Concealed; foci of Older

Pliocene volcanos

beneath Tuscany.
Metamor- f Concealed; probably near
phic. \ the same foci.

f Mont Perrier, Auvergne
- - J — Orleanais, Vol. JV.

(_ pp. 134. 137.
Bordeaux. Dax.

a. Marine.

b. Freshwater,

a, Plutonic.

b. Metamor-

phic.

a. Marine.

b. Freshwater,

f Saucats, near Bordeaux*
\ Vol. IV. p. 121.
Hungary, Vol. IV. p. 140-

{Concealed; foci of Mio-
cene volcanos — be-
neath Hungary.

f Concealed ; probably
\ around the same foci.

f Summit of North and
\ South Downs? Vol. iV.
[ p. 263.
Paris and London basins*

Isle of

Wight

Au-

vergne.

a. Plutonic.

b. Metamor-
phic.

f Ronca, Vicentine, ^°^'

J IV. p. 211.; oldest

■< volcanic rocks of the

I Limagne d'Auvergne>

(^ book iv. ch. xix.
Concealed; foci of Eocene

' volcanos — beneath Vi-
centine and the L 1 '

magne d' Auvergne.
Concealed; probably near

the same foci.

OF THE PRINCIPAL FORMATIONS.

397

TABLE II. — - continued.

Periods.

Formations.

Some of the Localities where

the Formations occur.

f Alluvial
i

Aqueous

• 1.
Creta-
ceous
group.

Table I.

p. 302. LHypogene

a. Marine.

Freshwater.

f Wiltshire,
\ Flambc

North Downs.
Flamborough Head.

Volcanic.

Alluvial.

2.
Wealden ■ Aqueous,

group. *

Table I.

Volcanic.

p. 302. Ljjypogene

Alluvial.

3.
Oolite
roup.

II.

Table I.
p. 303.

Aqueous.
Volcanic.

L Hy pogene.

f Alluvial.

Aqueous
i Vol

came.

4.
Lias
group.

Table I.

p. 304. |^ Hypogene

5. f Alluvial

New Red
Sandstone

and Mag-

nesia n

Aqueous

limestone I Volcanic.

group. I

K. & L. l^Hypogene
Table I.
p. 304.

Plutonic.
Metamor-

■

phic.

{Northern Flanks of the
Pyrenees ? Near Dax ?

fa. Marine.
\b. Freshwater.

/Portland " Dirt-bed"
L (containing pebbles).

{Weald of Surrey, Kent,
and Sussex, book iv.
ch. xxi.

Plutonic.
Metam or-
phic.

a. Marine.

b. Freshwater.

Plutonic.

Metam or-
phic.

a. Marine.

f Oxford. Bath* Jura
\ chain.

■

Hebrides ?
f Concealed ; beneath the
\ Hebrides.

f Lyme Regis.
\ Aberthaw.

Whitby

Freshwater.

Hebrides?

Plutonic.

Metamor- f Alps ? book iv. ch. xxvir,

phic. \ Valorsine in Savoy.

{Cheshire. Staffordshire,
Vosges. Westphalia
(jMuschelkalk.)

a. Marine.

b. Freshwater.

Plutonic

Near Exeter, Devon.

{Concealed; beneath De-
vonshire ?
Metam or-
phic

398

TABULAR VIEW OF STRATA.

■3

TABLE II. — continued.

Periods.

Formations.

Some of the Localities where
the Formations occur.

f Alluvial.

6.
Carbo ni-
ferous &
Old Red
Sand-
stone
group.

M.& N.

Table I.
p. 305,

Aqueous.

Vol canic.

Hypogene

a. Marine. -f C1 ! fton > Mendip, Ed*'

^ burgh.

{Coal measures of Nor*
of England and near
Edinburgh.

{Forfarshire. Edinburgh'
Fife. Durham. W 1
Teesdale.

{Concealed; beneath Ed* 11 '
burgh, Northufliber-

a. Plutonic.

r *.

Silu-
rian &
Grey-

wack£

group.
O. & P.
Table I,

"L p. 306.

Alluvial.

Aqueous.
^ Volcanic.

6. Met am or-
phic.

a. Marine.

b. Freshwater.

burgh,
. land, Durham.
f Near the Plutonic rocK*

\ of the same period*

Wenlock, Shropshire

Alluvial.
Aqueous
Volcanic,

b, Metamor-
phic.

> L

Shropshire.
Hypogene. \ * Hntadc. |^-W

J" Near the Plutonic rock*
\ of the same period.

{Probably all destroy**
by denudation, or co^
verted into hypoge* 10 '
f Perhaps a consider^*'

-J part of the gran ite

^ now visible.

f Probably a large prop ?*

I tion of the gneiss, &**

Metam orphic. V ,ca-schist, and otb^r

J stratified crystalK* 1 *

^ rocks now visible.

PI utonic.

Hypogene.

* By primary formations are meant those, whether stratified or m»'
stratified, which are older than the most ancient European rocks (**

ahco'vered ° r greyWa ° k ^' in which distin <* fo ^ls have as yet been

■

■•

INDEX

Aberdeenshire, passage from trap into
granite in, iv. 348.

Abesse, inland cliff at, iv. 124.

Abich, M., on slope on which lava con-
geals, ii. 173.

Abo, ii. 291, 292.'

Acquapendente, volcanic tuffs at, iv. 54.

Adams, Mr., on fossil elephant, i. 151.

Adanson on age of the baobab tree, iii.

428.
Addington hills, iv. 213.
Addison on Burnet's theory, i. 56.
Adernb, dip of strata near, iii. 401.
Adige, embankment of the, i. 280. ; iii.

170.
* — , delta of the, i. 350.
Adour, R., new passage formed by, ii. 24.

tertiary strata of, iv. 120.
Adria, formerly a sea-port, i. 351.
Adriatic, deposits in, i. 64. 67. 128. 351. ;

iii. 272.

gain of land in, i. 351.
, its form and depth, i. 351.
Adur, R., transverse valley of, iv. 238.
Africa, fossil shells of, mentioned by

ancients, i. 25.

heat, radiated by, i. 168.
currents on coast of, ii. 20. 32.
drift sands of deserts, iii. 188.
shaken by earthquake, ii. 953.
devastations of locusts in, iii. 95.
strata forming off coast of, iii. 272.
j desert of, its area, iii, 131.
Agassiz, M., on fossil fish, i. 20a 235. ;
iii. 358.; iv. 33. 112. 179. 279. 293. 296.
Agricola on fossil remains, i, 37.
Ahmedabad town, destroyed by earth-
i quake, ii. 194.

Aidat, lake, how formed, iv. 200.

Air, circulation of, i. 188.

Airthrey, fossil whale found at, iii.

267.
Airy, Professor, i. 185.

Aix, in Provence, tertiary strata of,
iv. 210.

, fossil insects of, iv. 210.

Albenga, tertiary strata at, iv. 64.
Aldborough, incursions of sea at, i. 414.
Alderney, Race of, i. 385.
Aleppo, earthquake of, ii. 194.
Aleutian isles, eruptions, &c. in, ii. 47-

204.
Alga?, depth at which some species live,

in. 9.

Allan, Mr. T., on mammiferous fossils

of Isle of Wight, i. 241. ; iv. 216.
Allier, R., volcanic tuff, &c. on its

banks, iv. 185.
Alloa, whale cast ashore at, iii. 266.
Alluvium, definition of, iii. 196.

, formed in all ages, iv. 44.

•, imbedding of organic remains in,
iii. 197.
•, marine, iii. 198.
-, volcanic, ii. 94.
•, in Scotland, ii. 241.

stalagmite alternating with, in
French caves, iii. 210.

Eu ropean, in great part tertiary.

iv. 45.
•, of newer Pliocene period, iv. 38,

44. 48.

— , of Miocene era, iv. 134.
•, of Eocene period, iv. 234. 263.
., under lavas, iv. 95. 98. 195.
\ in ancient fissures, iv. 198.
Alps, Saussure on the, i. 80.
., tertiary rocks of the, i. 210.

400

INDEX.

Alps, greatly raised during tertiary
epoch, i. 219.

, shells drifted from the, iii. 860.

•, erratic blocks of the, iv. 46.
maritime, tertiary strata at base
of, iv. 61.

secondary strata penetrated by

granite in the, iv. 344.

strata of oolite altered in the, iv.

Animals, hereditary instincts of, "• ^

, domestic qualities of, ii. 408. 413-

-, their acquired habits rarely trans-
missible, ii. 413. 421.
-, changes in the brain of the fte tus

369.

Altered strata in contact with granite,
iv. 368.

-, enumeration of the probable. con-
versions of sedimentary strata into

well-known metamorphic rocks, iv.
' 375.

Alting, on the Zuyder Zee, ii. 6.
Alum Bay, alternation of London and

plastic clay in, iv, 213.
Alzey, tertiary strata of, iv. 132.
Amalfi, i. 126.

Amazon, R., sea discoloured by waters
of, ii. 33.
■, land formed by its deposits, ii. 33.

,. animals floated down on drift

wood by, iii. 42.
Amer, structure of country near, iv. 91.
America, its coast undermined, ii. 9.
., lakes of, may cause deluges, i. 133.
recent strata in lakes of, i. 344. ;
iii. 262.

•, specific distinctness of animals of,

iii. 2. 27.
— — , domesticated animals have run

wild in, ii. 394. ; iii. 113.
Amiata, Mount, i. 314.
Amici, Vito, on Moro's system, i. 67.
Ammonia in lavas, ii. 351.
Amonoosuck, flood in valley of, i. 294.
Ampere, M., on currents of electricity

in the earth, ii. 324.

Anapo, valley of, iii. 442.

Andernach, loess and volcanic ejections

alternating at, iv. 34.
Andes, changes of level in, iii. 25a
, height of perpetual snow on, i.

194.

volcanos of, ii. 41. 43.
Anglesea, changes caused by a volcanic

dike in, iv. 364. 378.
Animals, Lamarck's theory of the pro-
duction of new organs in, ii. 368.

imported into America, have run
wild,ii. 394. ; iii. 113.

■, aptitude of some kinds to do-
mestication, ii. 408. 417.

in vertebrated, i. 439.

j plants diffused by, iii. 17.
— , their geographical distribution*

i. 204. ; iii. 27.
», migrations of, iii. 33. 36*
-, causes which determine thesta*
tions of, iii. 86. 98.

.influence of man on their distribu-
tion, iii. 109.
, fossil, in peat, caves, &c., iii. ^'

187. 197. 201. 231. 236.
Anio, R., flood of the, i. 298. f

, once flowed through a chain °

lakes, i. 324.

Anning, Miss M., on waste of cli^'
i. 429.

Annus Magnus, duration of, i. 12.

Anoplotherium in freshwater forma-
tion of I. of Wight, iv. 216. 263.

Anthracite, whence derived, iv. 37&

Anticlinal axis of Weald valley, iv '
224. 231.

Anticlinal lines ; how far those form^

at the same time are parallel, iv. 34*

Antilles, earthquake in the, ii. 207-
Antissa, i.^18.

Antrim, chalk in, converted into ma 1 *

ble by trap -dike, iv. 365.

, altered coal and lias in, iv. 366.

Apennines, their relative age, i. 209. #&

, tertiary strata at foot of, iv. 49.

Aphides, White's account of a shoW#

of, iii. 65.

, their multiplication, iii. 93.

Apollinaris cited, iv. 200.

Apure, R., horses drowned in, iii. 93^

Aqueous causes, i. 259.

Aqueous lavas, description of, ii. 78. 9*'
iii. 192.

Arabian Gulf, filling with coral, iii. ^ 8 °'.

•, volcano at its entrance, ii. 58.
Arabian writers, i. 24. 29.
Arago, M., on influence of forests on
climate, iii. 168.
., on solar radiation, i. 226.
., on level of Mediterranean and R e °\
sea, i. 387.
Arbroath, houses, &c. swept away W

sea at, i. 400.
Arduino, memoirs of, 1759, i. 72.
■, on submarine volcanos, i. 73. 12&

A
A\

A
Ai

Ai
A
A
A

INDEX.

401

Aristarchus, i. 299.

Aristophanes, i. 16.

Aristotelian system, i. 21.

** — theory of spontaneous generation,

i.38.
■Arno, R., yellow sand like Subapennine

deposited by, iv. 56.
Arso, volcanic eruption of, in Ischia,

ii. 70.
•Artesian wells, phenomena brought to

light by, i. 302.
, depth from which water rises in,

i. 303.
•Arun, transverse valley of the, iv. 238.
■Arve, sediment transported by the, i.

345.

***-*, section of debris, deposited by, i.
378.

■Asama-yama, eruption of, ii. 209.

Ascension, island of, fossil eggs of tur-
tle from, iii. 267.

Ashes, volcanic, transported to immense
distances, ii. 201.

Asia, subject to earthquakes, i. 14.

•, coast of, changed, i. 30.

■i causes of extreme cold of part of,

i. 168.

Minor, gain of land on coast of,

ii. 32.

•> Western, great cavity in, iii 126.

■, this now doubted, iv. 202.
"Ass, wild in Quito, iii. 115.
"*--» wild in Tartary, iii. 38.
Astroni, crater of, iv. 94.
Astruc on delta of Rhone, i. 346.
"Atchafalaya, R., drift-wood in, i. 286.
v — s section of the banks of, i. 365.
Athabasca lake, drift-wood in, iii 222,
"Atlantic, mean depth of, i. 185.

•, its relative level, i. 387. *

. rise of the tide in, i. 388.
•Atlantis, submersion of, i. 14. ; iv. 309.
•Atrio del Cavallo, ii. 88. ; iv. 9.
Aubenas, fissures filled with breccia
*ear, iii. 210.

^rillac, freshwater formation

158.

"^stralia, kangaroo and emu thinning
% iii. 112.

> coral reefs of, iii. 280.

> breccias of, bones of marsupial

Animals in, iv. 43.

^ v ergne, salt deposited by springs in,
l - 331.

of, iv.

331,

carbonic acid gas disengaged in, i.

Auvergne, lavas of, iii. 422.
., alluviums of, iv. 134. 195.
■, volcanic rocks of, i. 86, 87. ; iii.
365. ; iv. 142. 184.
-, lacustrine deposits of, iv. 144.
map of lacustrine basins and vol-
canic rocks of, iv. 145.

•, tertiary red marl and sandstone of,
like new red sandstone, iv. 148. 316.
— , indusial limestone of, iv. 152.
— -, connexion of Paris basin and, iv.
165.

-, igneous rocks 'associated with la-
custrine in, iv. 185.
-, volcanic breccias of, iv. 134. 187.
-, minor volcanos of, iv. 188. 192.
ravines in lavas of, iv. 194. 195.
Ava, fossils of, i. 49.
Aventine, Mount, tufa on, iv. 28.
Avernus, lake, ifc 65.
Avicenna on cause of mountains, i. 30.
Azof sea, said to have been united with
Caspian, ii. 52.

', new island thrown up in, ii. 53.
Azores, icebergs drifted to the, i. 177.

271.
, siliceous springs of, i. 327.

Babbage, Mr., on the coast near Puz-

zuoli, ii. 268.
, on Temple of Serapis, ii. 280.

, on expansion of rocks by heat, ii.

339.
Bacon, Lord, cited, iii. 257.
Baden, gypseous springs of, i. 326.
Baffin's Bay, icebergs in, i. 172.
Bagnes, valley of, bursting of a lake in

the, i. 295.
Bagneux, strata near, iv. 168.
Bagshot sand, its composition, &c, iv.

215.

Baia*, changes on coast of the bay of, ii.
267.

> ground plan of the coast of, ii. 267.

9 sections in bay of, ii. 269. 271.
Bakewell, Mr., on formation of soils,

iii. 156.

, on fall of Mount Grenier, iii. 200.

, on jointed structure in rocks, iv.
S59.
Bakewell, Mr., Jun., on Falls of Nia.
gar a, i. 276.

Bakie loch, charze fossil in, iiu 260, ,

i ■

402

INDEX.

Baku, inflammable gas of, i. 19. ; ii. 51.
Balaruc, thermal waters of, i. 347.
Baldassari, on Sienese fossils, i. 68.
Ballard, M„ on state of buried bones,

iii. 214.
Baltic sea, deltas of the, i. 344.

, lowering of level of the, i. 345. ;

ii. 286.

drifting of rocks by ice in, i. 271.
., currents on its shores, ii. 12.
Banos del Pujio, elevated sea-cliff near,
iv. 17.

Baobab tree, its size, probable age, &c.
iii. 428. ; iv. 205.

Barbadoes, rain diminished by felling of
forests in, iii. 165.

Barcelona, tertiary strata of, iv. 101.

Barcombe, in Sussex, iv. 234.

Bargone, gypsum in marls near, iv. 54.

Barren island, a supposed crater of ele-
vation, ii. 159.

Barrow, Mr., on a bank formed in sea
by locusts, iii. 96.

Barrow, Mr., Jun., on the Geysers of
. Iceland, i. 329. ; ii. 342.

Barsoe, loss of land in island of, ii. 12.

Barton, Mr., on geography of plants,

m. 2.

Basalt, opinions of the early writers
on, i. 85, 86. ; iii. 307.

Basterot, M. de, on fossil shells of Bor-
deaux and Dax, iii. 338. ; iv. 119.

Batavia, effects of earthquake at, ii. 259.

Battoch, Mount, granite veins of, iv.

342.
Baumhauer, Mr., on a river-flood in

Java, iii. 235.
Bauza, his chart of Gulf of Mexico, ii.

34.

Bawdesey, crag strata near, iv. 79. |

Bay of Bengal, its depth, i. 359.

Bayfield, Capt, on geology of Lake Su-
perior, i. 342.

on bursting of a peninsula by Lake

Erie, ii. 12.

on elevated beaches in Gulf of St.
Lawrence, ii. 47. ; iv. 20.
., on earthquakes in Canada, ii. 208.
., on arrangement of strata in Gulf of
St. Lawrence, iv. 58.
Bayonne, strata near, iv. 124. 327.
Beachy Head, i. 423. ; iv. 228.
Bears, once numerous in Wales, iii.

111.

black, migrations of, iii. 36.

drifted on ice, iii. 103.

Beauchamp, palaeotherium of, iv. *«*
Beaufort, Capt., on gain of land on coa
of Asia Minor, ii. 32.

, on rise of tides, i. 382. . •

Beaumont, M. Elie de, on greywacK

fossils, i. 201.

, on the Great Canary, ii. 158.

, on elevation craters, ii. 171.

., on force of modern earthquaKe ,

ii. 357.

on cause of the deluge, iv. 205.
, his theory of contemporaneo
origin of parallel mountain cna
considered, iv. 320.

, on modern granite of the Alp s

344.

Beaver, once an inhabitant of Scotia
and Wales, iii. 110. .

., remains of, in shell-marl, in P er

shire, iii. ^36.
Beck, Dr., on distribution of testace »

iii. 56.
., on fossils of the Crag, iv. 72.

, on tertiary strata of Denmark

88.

ofs ° { >

Bee, migrations of the, iii. 64. f

Beechey, Capt, on elevation of # aV
Conception, ii. ^56. .~ c

on drifting of canoes in P& cl
iii. 72.

-, on temple of Ipsambul, iii. 1° Q oo
— , on coral islands in Pacific, in*

287.297. . fr

, on recent changes of level * n

cific, iii. 296.
Beginning of things, supposed pr°

iv. 392.
Behat, buried town near, iii. 199.
Belbet, near Aurillac, iv. 160. -

Belcher, Capt, on elevation of Co& *

tion Bay, ii. 256. . f

— , on strata forming off c ° a

Africa, iii. 273. mq

Belgium, tertiary formations of, lV *
Beliemi, Mount, caves in, iv. 42.
Bell rock, large stones thrown UP

storms on the, i. 400. .. *ag,

Belzoni, on temple of Ipsambul, in.

, on a flood of the Nile, iii- ^'

Benin, currents in bay of, i. 383. ^

Berard, M., on depth of Mediterran

ii. 18. m oa st,

Bergmann, on waste of Yorkshire

i. 404. iii.

Berkeley, on recent origin of m a '

255.

X>1

fcerl

* I

Hi:
Hi:

Hi;
Hi,

Hi:

Hi;

Hi,

Hi.
Hi,

Hi,
Hi,

Hlj
Hi

INDEX.

403

^mudas, coral reefs of the, iii. 279.
283.

^ er thelot, M., on the Great Canary, ii.

158.

^erzelius, on density of sea-water, i.

172.

^ es htau, earthquakes in, ii. 250.

^ e Udant, M. , on volcanic rocks of Hun-

. 8ary, i v . 140.

^ e Mck, cited, i. 413. ; iii. 47. 111.
k°oj, town of, destroyed by earth-
quake, ii. 195.

^-j volcanic eruption at, during Cutch

earthquake, ii. 195. ; iii. 194.

^es Bosch ; new bay formed in Hol-
loa, ii. 5.

%sby, Dr., on North American lakes,

J- 343. ; iii. 262.
^jftgen, gorge of, iv. 35.
{^stead, fossils of, iv. 216. 263.
Bi * ds, diffusion of plants by, iii. 18.
', geographical ^distribution of, iii.

^5. 74.
•» their powers of diffusion, iii. 47.

•, migrations of, iii. 47.
-5 recent extermination of some spe-
cies of, iii. 111.
•, bones of, in Gibraltar breccia, iii.

209.

■, rarity of their remains in new
strata, iii. 230.

jrjschoff, Professor, cited, iv. 372.

ls coe, Capt, his discoveries in the
.south Polar Seas, i. 175.
^| s on, fossil, in Yorkshire, i. 145.
frjsons, in Mississippi valley, iii 35.
^istineau, a lake formed by Red River,

J; 290.

^tumen, oozing from the bottom of the
., s ea, near Trinidad, i. 334.

luminous springs, i. 334.

. -, shales, i. 335,

j*;ze, cave at, iii. 213.

. I2 ona, town submerged, i. 27.

j* l ack Lake, i. 290.

™ack Sea, calcareous springs near, i.

325.

•i waste of cliffs in the, ii. 12.
evaporation of the, ii. 15.
. > see Euxine.
Javier, M., on peat, iii. 179. L'
^aye, limestone of, iv. 122.
Cornfield, bursting of peat-moss near,

lQ wn sand, imbedding of organic re-
gains, &c. in, iii. 188.

Blue mountains in Jamaica, ii. 264.
Bluffs of Mississippi described, i. 283.

285.
Boa Constrictor, migration of, iii. 51.
Boase, Mr., on inroads of sea in Corn-
wall, i. 429, 430.
, on drift-sand in Cornwall, iii. 191.
, on chemical composition of rocks,
iv. 377.
Boate, Dr., on Irish peat-bogs, iii. 178.
Boblaye, M., on ceramique, in Morea,
iii. 200.

, on engulphed rivers in Morea, iii.
204.
, on caves of the Morea, iii. 204.
, on earthquakes in Greece, iii. 207.
, on successive elevations of the
Morea, iv. 20.
, on tertiary strata of Morea, iv. 70.
, on cretaceous rocks of Morea, iv.
277.

Bog iron-ore, whence derived, iii. 182.
Bogota, earthquake of, ii. 189.
Bohemia, age of metallic veins of, iv.
375.

Bolos, Don Francisco, on volcanos of
Catalonia, iv. 94. 99. 101.

, on destruction of'Olot by earth-
quake, in 1421, iv. 99.

Bonajutus, on subsidence of coast of
Sicily, ii. 261.

Bonaparte, C, on birds, iii. 47.

Bonelli, Signor, on fossils of theSuperga,
iii. 364. ; iv. 126.

— , on fossil shells of Savona, iv. 64.

Bonn, casts of freshwater shells in
quartz, near, iv. 112.

Bonpland, on plants common to Old and
New World, iii. 5.

Bordeaux, tertiary strata of, iii. 338. ;
iv. 119.

Bore, a tidal wave frequent in the Bris-
tol Channel and the Ganges, ii. 10.

Bormida, tertiary strata of valley of the,
iii. 364. ; iv. 127.

Bory de St. Vincent, M., on isle of San-

torin, ii. 161. 164.
Boscomb chine, i. 427,
Bosphorus, ii, 15. 52.
Botanical Geography, iii. 3.

, provinces, their number, iii. 7.

, how caused, iii. 80.

, why not more blended together,

iii. 82.

Bothnia, Gulf of, gradual elevation of
the coast of, i. 217. 345. j ii. 287. ,

• • ft

404

INDEX,

Bothnia, Gulf of, drifting of rocks by

ice in, i. 271.
Botley Hill, height of, iv. 224.
Bou£, M.. on the Pyrenees, i. 211.
-, on the coal strata, i. 202. ;
., on loess of the Rhine, iv. 38.
., on value of zoological characters
in determining the chronological re-
lations of strata, iv. 123.

•, on tertiary formations of Hungary
and Transylvania, iv. 129. 141.
— , on the Vicentine, iv. 211.

on theory of M. de Beaumont, iv.

331. 333.

Bouiilet, M., on extinct quadrupeds of

Mont Perrier, iv. 136. 197.
-, on alluviums of different ages in

Auvergne, iv. 197.
Boulade, alluviums of the, iv. 134.
Boulon and Ceret, dip of tertiary strata

between, iv. 70.

Bourbon, island, volcanic, ii. 58. ; iv.
350.

Bourdones, R., shoal upheaved at its
mouth, ii. 208.

Bournmouth, submarine forest at, iii.

228.

Boussingault, M., on volcanos of the
Andes, ii. 43, 44.

■, on gases evolved by volcanos, ii.
348.

Bowdich, Mr., on fossil shells of Ma-
deira, iv. 24.

Bowen, Lieut. A., on limestone columns

near Mingan, iv. 21.
Boyle on bottom of the sea, i. 44.
Bracini on Vesuvius before 1631, ii. 77.
Brahmins, their doctrines, i. 9.

Brand, Rev. J. F., on birthplace of man,
iii. 68.

Brander on fossils of Hampshire, i. 77.
Bray, valley of, iv. 287. •
Breaks in series of superimposed form-
ations, causes of, iii. 315. 351.
Breccias, in Val del Bove, iii. 422.
., in caves, iv. 38. 43.

1 ., now in progress in the Morea, iii.
205.
., volcanic, of Auvergne, iv. 134. 187.
Brenta, delta of the, i. 350.
Brieslak, on the temple of Serapis, ii.
276. 278.
>, on lavas of Vesuvius, ii. 90.
Briggs, Mr., his discovery of water in

African desert, i. 304.
Brighton, waste of cliffs of, i. 424.

Brighton, strata at base of cliffs at, 1 -

422. ; iv. 261. 267.
Brine springs, i. 330.
Bristol Channel, currents in, i. 385:
Britany, a village in, buried una

blown sand, iii. 191.

, marine tertiary strata of, i. ^'

Brocchi on fossil conchology, i. 34.

, on Burnet's theory, i. 59. e

, his account of writers on delta

Po, i. 351.

, on extinction of species, iii. 83.

•, on the Subapennines, i. 209. J n '

335 t ; iv. 49. 60.

Broderip, Mr., on opossum of Stones
field, i. 238. ..

•, on shells from Conception BaT> J '
257.

, on Ianthinafrctgilis, iii. 56.

, on bulimi restored to life at 1 "

long abstinence, iii. 58.
■, on moulting of crabs, iii. 60. ,
, on naturalization of a foreign latf°-

shell, iii. 76.

Bromberg, a vessel and two anchor

.last*

up near, iii. 247.
Bromley, pebble with oysters in p

clay at, iv. 212. r

Brongniart, M. Ad., on fossil plants

the coal formation, i. 158.

, on plants in islands, i. 196.

Brongniart, M. Alex., on modern te va ~

streams, ii. 132.
■, on elevated beaches in Sweden*

216. 5 ii. 299.
, on the Paris Basin, iii. 33'

166.172.
— , on conglomerate of the Supers *

iv- 127. „ e

Bronn, Prof., on fossil shells oi

Superga, iii. 367.
. , on tertiary formations of Italy*

33% ; iv

367.

, on loess of the Rhine, iv. 32. #•.
, on tertiary strata of Mayence

iv.

133.

• ii. *--• .
Gulf oi

•- V21

Bronte, eruption of Etna, near. n- l
Browallius, on filling up of

Bothnia, ii. 291. .*.

Brown, Mr., on plants common to

rica, Guiana, and Brazil, iii. 1*>»
Brown coal formation near the R nl

iv. 110.
Bruel, quarry of, iv. 160. &f . 9

Buckland, Dr., on fossil elephants,
in India, i. 9.

ii:

*U:
C

fcurl

«ut:

%r<

INDEX.

405

Uc Mand, Dr., on fossils from Esch-
scholtz's Bay, 1. 153.
» on the Bristol coal-field, i. 205.
3 on mammiferous remains of Isle of
^ight, i. 241.

on fossils in caves and fissures, iii.
308. 210. 212.
■> on Val del Bove, iii. 407.
on effects of the deluge, iv. 203.
> on the Plastic clay, iv: 212.
■> on former continuity of London
ar *d Hampshire basins, iv. 219.

on valleys of elevation, iv. 246. 249.
•, on fossil forest of I. of Portland,
^. 285.
k*-* 5 on oolite fossils, iv. 310.
j^doshagy, solfatara of, iv. 142.
^Ufadors, jets of air from subterranean

.caverns called, iv. 98.
^Won, his theory of the earth, i. 68.
reproved by the sorbonne, i. 69.
, on geographical distribution of ani-
mals, iii. 2. 27.
. "*•, on extinction of species, iii. 143.
^limus montanus drifted from Alps,
fci. 360.
u *a and Helice, submerged Grecian

towns, i. 27.'; ii. 56.; iii. 255.

j^ckhardt cited, iii. 189, 190.

^rdiehouse fossils, i. 203. ; iv. 294.

u *ied cones on Etna, sections of, iii.
415.

j) u rkart, Mr., on Jorullo, ii. 137.
^fnes, Capt. A., on earthquake of
Cutch, 1819, ii. 196.
, on earthquake in valley of the

k °xus, ii. 50.

j^rnet, his theory of the earth, i. 55.
Ur ntisland, whale cast ashore near,

Jii. 266.

Ur rampooter, bodies of men, deer, &c.

boated off by, iii. 234.
k "*-> delta of the, i. 558.

Ut ton, Mr. J., on tertiary strata near
. fted Sea, iv. 25.

u stards, recently extirpated in Eng-

knd, iii. 111.

ut ler, Burnet's theory ridiculed by, i.

56.

Vr on, Lord, on permanency of the
°cean, ii. £85.

^ibona, lignites of, iv. 139.
^o lake, i. 290,

Caasar cited, i. 27."; iv. 200.
Cairo, fossil shells at, iv. 127.
Caithness schists, fossils in, i. 235.

Calabria, geological description of, ii.

214. " '

earthquake of 1783 in, ii. 210.

■—, animals preserved in fissures in,
in. 209.

, ^^.y anauiur, i. i4i.. iii. 340 o

Calais, ripple marks formed by the

winds on dunes near, iv. 81.
Calanna, lava of Etna turned from its

course by hill of, iii. 412.
- — , valley of, iii. 411. 419.
Calcaire grossier of Paris basin, iv. 167;

169. 173. 179.
Calcaire siliceux of Paris basin, iv. 170.
Calcareous springs, i. 311.

Calcutta, beds cut through in sinking i
well at, i. 361.

Caldcleugh, Mr., on earthquake in Chili,

1835, ii. 185. .*

Caldeira, siliceous sinter of the, i. 327 '
Caldera, in Isle of Palma, ii. 155. . £k

290. '

California, volcanos in, ii. 45.
Callao, town destroyed by sea, ii. 53.
, changes caused by earthquakes in.

ii. 258, 259. ; iii. 253.

Caltabiano, R., lava excavated by, L

274.

Caltagirone, blue shelly marl of, iii. 386.
Caltahisetta, tertiary strata at, iii. 387.
Cambrian formations, iv. 300. 306.
Camden cited, i. 431.

Camels, carcasses of, imbedded in drift
sand v iii. 190.

Campagna di Roma, calcareous deposits
of, i. 320.

> volcanic rocks of, iv. 89. '

Campania, aqueous lavas in, iii. 192,

, tertiary formations of, iv. 1.

comparison of recorded changes in
with those commemorated by geolo-
gical monuments, iv. 1.

■, age of volcanic and associated
rocks of, iv. 11.

■, external configuration of the coun-
try, how caused, iv. 13.

S affords no signs of diluvian waves,
iv. 14.

Campbell, Mr., on migration of quaggas

in South Africa, iii. 38.
Camper, on facial angle, ii. 437.
Canada, earthquakes frequent in, ii.

46. 203.

■

406

INDEX

Canary islands, eruptions in, ii. 58.

, shells between lavas in, ii. 158.

Cannon in calcareous rock, iii. 249.
■, account of one taken up near the

Downs, iii. 249.

Canoes drifted to great distances, iii. 71.

— -, fossil, iii. 248.

Canopus, formerly an island, i. 354.

', overwhelmed by the sea, i. 356.
Cantal, Plomb du, ii. 170.

•, freshwater formations of, iv. 158.
Capellbacken, shelly deposit at, ii. 299.
Cape May, encroachment of sea at, ii.
10.

of Good Hope, icebergs seen off,
i. 177.

Wrath, granite veins of, iv. 346.

Capitol, hill, calcareous tufa on, iv. 28.
Capo Santa Croce, shelly limestone

resting on lava at, iii. 390.
Capra, rock of, iii. 420.
Caraccas, earthquakes in, ii. 202. 208.
Caradoc sandstones, iv. 270, 271. 299.
Carang Assam volcano, ii. 202.
Carbonated springs, i. 331.
Carbonic acid gas ; its effects on rocks,

i. 331. 333. ; iv. 374.

Carboniferous series, i. 201. 235.; iv.
293.

■, freshwater strata in, iv. 294.

•, see Coal

Carcare, tertiary strata of, iv. 121. 127.

Cardiganshire, tradition of loss of land
in, i. 431.

Cardium porulosum, iv. 175.

Cardona, rock salt of, its relative age,
iv. 316.

Carelli, Signor, on temple of Serapis, ii,
273.

Carew on St. Michael's mount, i. 430.

Cariaco, bed of sea raised near, ii. 250.

Caribbean sea, tides in, i. 388.

Caridi, R., its course changed by earth-
quakes, ii. 230.

Carlingford bay, raised beaches in, i. 216 .
Carpenter, Dr., on encroachment of sea

at Lyme Regis, i. 429.
Casalmaggiore, island at, carried away

by the Po, i. 280.
Casamicciol, shells in tuff at, iv. 12.
Caspian, Pallas on former extent of, i.
80.
•, calcareous springs near the, i. 326.
■, evaporation of the, i. 350.
., earthquakes on its borders, ii. 51.
., inflammable gas, &c. near, ii. 51.

Caspian, its level, ii. 51.; iii. 126.; & ^
— , said to have been united ^i

Black Sea and sea of Azof, ii- bl ' '

iii. 45.
Cassander cited, i. 13. - n

Castell de Stolles, ravine excavated *

lava opposite, iv. 96. Q .
Castell Follitt, lava stream of, * v - *'
, lava cut through by -river at,

97.
Castello d'Aci, iii. 405. ,

Castrogiovanni, section of Val di *°
series at, iii. 385.
, hill of, its height, iii. 386.
, fossils of, iii. 389. ...

Catalonia, devastation of torrents in> l '
164.
■, volcanic district of, iv. 90.
, ravines excavated through la* a l '
iv. 95. 97.

— , age of volcanos of, iv. 99. ^

— , superposition of rocks in volc» n
district of, iv. 100.
Catania, overwhelmed by lava, &
iii. 193.

, destroyed by earthquakes, ii* "° ',j
, tools discovered in digging a ^ '

11S> '>

at, iii. 246.

, volcanic conglomerates form^
beach at, iii. 396.
— , plain of, iii. 397.

, marine formation near, iii. 40& .
Catastrophes, theories respecting, *• * '

iii. 309. 353.
Catcliff, Little, section of, iv. 80.
Catcott on the deluge, i. 74. n t

on traditions of deluges in diff ere
countries, i. 74.
Catodons, stranded, iii. 266. n t

Cattegat, devastations caused by c utre

in the, ii. 12.
Catwyck, loss of land at, ii. 5. .

Caucasus, calcareous springs of, i- ^q,

, earthquakes frequent in, ii. &

, abounds in hot springs, ii. 53.
Cautley, Capt., on buried Hindoo to* '

, on bones in ancient wells, m- - .j

Cavalaccio, Monte, shells in tuffs of,

402. # iit

Cavanilles on earthquake of Quito?

207. ' 5i .

Caves, organic remains in, iii. 201. ^

iv. 38. 42, 43. ^
, alternations of sediment ana

lagmite in some, iii. 210.

INDEX.

407

c aves on Etna, ii. 120.
Cavo delle Neve, in Ischia, iv. 13.
Cayambe, volcano, ii. 43.
Ceilent, lava current of, iv. 91.

• , section above bridge of, iv. 95.

Celestial mountains, i. 147.
Celsius on diminution of Baltic, 1. 58. ;
ii. 286.

Censorinus, i. 21. f

Central France, lavas excavated in, i.

272.

■, comparison between lavas of Ice-
land and, ii. 129. 131.

•, volcanic rocks of, iv. 142. 184.

., freshwater formations of, iv. 144.

■, analogy of tertiary deposits of, to
those of Paris basin, iv. 164. 172.
Central heat and fluidity, theory of, i.

221. ; ii. 313.

Centrifugal force, ii. 309. 329.

Cephalaspzs, fish fossil in old red sand-
stone (see fig.), iv. 296.

Cephalonia, earthquakes in, ii. 214.

Cer, valley of, sections in the, iv. 161.

Ceret and Boulon, tertiary strata be-
tween, iv. 70.

Cesalpino on organic remains, i. 38.

Cetacea, geographical range of, iii. 33.
-, migrations of the, iii. 44.
., imbedding of their remains in re-
cent strata, iii. 266.
•, stranded on low shores, iii. 266. '

Chabriol, M., on fossils of Mont Per-

rier, iv. 136.
Chadrat, pisolitic limestone of, iv. 152.
Chagos coral isles, iii. 280.
Chalk, protruded masses of, in the crag

strata, iv. 85.
., indentations" filled with sand, &c,

on its surface, iv. 217.
■, tertiary outliers on, iv. 218.
and upper green sand of Weald

valley, iv. 223.

escarpments of Weald valley, once

sea-cliffs, iv. 227, 228.
f , why no ruins of, on central district

of the Weald, iv. 234.

of North and South Downs, its

former continuity, iv. 244.
•, furrows on the, how caused, iv.

217.
-, greatest height of, in England,

iv. 259.
., area covered by, iv. 275.
., converted into marble by trap dike

in Antrim, iv. 366.

Chalk-flints, analysis of, iv. 160.
Chaluzet, calcareous spring at, i. 312.

■ , volcanic cone of, i. 33%.

Chama gigas, growth of, iii. 282.
Chamalieres, near Clermont, iv. 147.
Chambon, lake of, how formed, iv. 193.
Chamisso, M., on coral islands, iii. 278.
Chamouni, glaciers of, iv. 47.
Champheix, tertiary red marls of, iv.

148.
Champoleon in the Alps, strata altered

near, iv. 369.
Champradelle, vertical marls at, iv. 151.
Charts, fossilized, iii. 259.
Charles worth, Mr., on the crag strata,

iv. 73, 74.
Chemical changes, whether volcanic

heat is produced by, ii. 320.
Chepstow, rise of tides at, i. 382.
Cheshire, brine springs of, i. 330.

, waste of coast of, i. 431.

Chesil bank, i. 427.

Chesilton, overwhelmed by sea, i. 428.

Chili, earthquakes in, i. 117. ; ii. 183.

189.
, numerous volcanos in, ii. 41.

, Newer Pliocene marine strata at

great heights in, iv. 16.

Chimborazo, height of, i. 181.
China, climate of, i. 169.

, earthquakes violent in, ii. 50.

Chinese deluge, i. 10.

Chines, or narrow ravines, described,

i. 427.
Chittagong, earthquake at, ii. 250.

Chockier, cave at, iii. 211.

Christ Church head promontory, i. 426.

Christie, Dr. T., on caverns in Sicily,
iv. 39. 41, 42.

Christol, M. de, on fossils of Montpel-
lier, iv. 126.

■, on caves, iii. 214, 215.

Cicero cited, i. 42.

Cimbrian deluge, ii. 13.

Cinquefrondi, changes caused by earth-
quake at, ii. 232.

Ciply, Maestricht beds seen at, iv. 271.

Cirque of Gavarnie, in Pyrenees, iii.

415.
Circular hollows formed by earthquakes,

ii. 234.
Cisterna on Etna, how formed, iii 425. ;

iv. 15.
Civita Vecchia, springs at, i. 320.

Clarke, Dr., on appearance, &c. of lava
in motion, ii. 83.

;

■

408

INDEX

Clay-slate in Pyrenees, iv. 362.

, may be altered into shale, an
hornblende schist, iv. 376.
Clayton, Bishop, on the deluge, i. 74.
Cleavage, or slaty structure of rocks, iv.

354.
Clermont, sections near, iv. 147. 151.

185.

calcareous springs at, i. 312. I

Clift, Mr., on bones of animals from

Australian caves, iv. 44.
Climate of Europe, Raspe on former, i.
, 75. I

►, change of, in northern hemisphere,

i 138.

— , on causes of vicissitudes in, i. 164.

■, astronomical causes of fluctuations
in, i. 224.

, its influence on distribution of

plants, iii. 3.

, effect of alterations in, on distri-
bution of species, iii. 134. 138. 331.
influence of vegetation on, iii.

165.
Climates, insular and excessive, i. 169. ;

ii. 390.

Coal, formation of, at mouths of Mac-
kenzie, iii. 222.

, reduced to cinder by trap dike, iv.

367.
— . See Carboniferous.

Coal formation, fossil plants of the, i.

158. 202. 231. 243.
Cole, Viscount, on delta of the Kander,

iv. 69.
Colebrooke, Mr. H. T., on crocodiles of

Ganges, i. 362.
Colebrooke, Major R. H., on the Ganges,

i. 361. ; iii. 170.
Colle, travertin of, i. 313.

, freshwater formation of, iv. 28.

College, R., transportation of rocks by

the, i. 268.
Collini on igneous rocks, i. 86.
Colombia, earthquakes in, ii. 250.
Colonna on organic remains, i. 39.
Comb Hurst, hills of, iv. 213.
Come, lava current;of, iv. 93.
Conception, earthquakes at, ii. 185. 256.;

iii. 253.
., recent fossils at great heights in

, Bay of, iv. 16.

Conglomerates, tertiary, of Nice, iv. 65.

, now formed by rivers near Nice,

i. 375. ; iv. 65. 68.

•j volcanic, ii. 143. ; iii. 396.

Contemporaneous origin of rocks, how
determined, iii. 322.

, remarks on the term, iii. 363.

Continents, position of former, iv. 30 jr
Conybeare, Rev. W, D., on Lister, i. ^

, on Bristol coal-field, i. 205.

■, on earthquakes, ii. 357.
-, on the English crag, iii. 337,
-, on the London clay, iv. 214.
•, on indentations in the chalk,
217.

•, on transverse valleys, iv. 238.
— •, on vertical strata of Isle of Wight,
iv. 253.

•, on former continuity of chalk ot
North and South Downs, iv. 244.
-, on theory of M. E. de Beaumont,

iv.

iv. 333.
Cook, Captain, on drifting of canoes to

great distances, iii. 71.
•, on existence of high land near the

South Pole, i. 177.
Coomb, ravine called the, near LevveS*

iv. 241.
Copernican theory, edicts against, * e *

pealed at Rome, i. 100.
Copiapo, raised banks of shells at, ***

191.
Coquimbo, parallel roads of, iv. 18.
Coral between lava currents in "West

Indies, iii. 294.
Coral islands, iii. 274.
, beds of oysters, r &c, on, in the

Pacific, iii. 276.

, their extent, iii. 280. 294. 9,98.

-, linear direction of, iii. 280.
, rate of growth of, iii. 282.

Cordier, M., on rate of increase of h ea
in mines, ii. 313. 317.
., his theory of central ,heat and

fluidity, i. 222. ; ii. 314.

— , on tides in the internal melted

ocean, ii. 319.
Cordilleras shaken by earthquakes, **■

189. 203.
Corinth, decomposition of rocks in, lU '

203. ; iv. 374.
Cornwall, waste of cliffs of, i. 429.
., land inundated by drift sand i n >

iii. 191.
-, temperature of mines in, ii. 313.

, granite veins of, iv. 340. 368.

Corbmandel, inundations of sea on coast

of, iii. 198.
Cortesi, i. 79.

Cosmogony distinct from geology, i> 5'

INDEX.

409

Cosmogony of the Hindoos, i. 6.
, Egyptian, i. 12.
of the Koran, i. 31.
Costa de Pujou, hill of, iv. 93.
Costantini, deluge vindicated by, i. 60.
Cotentin, tertiary formation of the, iv.

208.
Cotopaxi, ii. 43. 337.
Coudes, tertiary red sandstone of, iv.

148.
Covelli, M., on increase of temperature
of a hot spring in Ischia by earth-
quake, ii. 188.
Cowper, i. 98.

Couze, R., lake formed by filling up of

its ancient bed by lava, iv. 193.
Crag of England, fossils of the, iii. 33Q .
iv. 71, 72. 75.

, its age, composition, &c, iv. 71.

, lacustrine deposits resting on the
iv. 77.
, stratification of the, iv. 78.

•, compared to Faluns of Touraine,
iv. 116, 117.

«, its resemblance to formations now
in progress, iv. 82.

Cramer, Mr., on earthquake of New

Madrid, ii. 204.
Crantz on drift-wood, iii. 224.

Craters of elevation, Von Buch's theory
of, considered, ii. 152.

Crawfurd, Mr., his discovery of fossils

in Ava, i. 50.
Creation, supposed centres or foci of,

iii. 81.
Cremona, lakes filled up near, i. 279.
Creta, argillaceous deposit called, iii.

387. 397. 401.
Cretaceous group, iv. 271.
Crimea, waste of cliffs in the, ii. 12.
Crocodile taken in the Rhone, iii. 50.
Crocodiles imbedded by a river inunda-
tion in Java, ii. 260. ; iii. 230. 234.
Croizet, M., on extinct quadrupeds of

Mont Perrier, iv. 136.

, on alluviums of Auvergne, iv. 197.

Cromer, waste of cliffs of, i. 406.

, section near, iv. 83.

Cropthorn, fossils found at, i. 145.
Crowborough hill, height of, iv. 224.
., thickness of strata removed from

summit of, iv. 259.
Cruckshanks, Mr. A., on earthquake of

Chili in 1822, ii. 190.
-, on lines of ancient sea-cliffs on

coast of ?eru, iv. 17.

Cuckmere, transverse valley of the iv

238. '

Culver cliff, i. 425.

Cumana, earthquake of, ii. 207.

Cumberland, slate rocks of, iv. 354. 382.

Cuming, Mr., on earthquake at Valpa-
raiso, 1822, ii. 191.

Currents from equatorial regions, i. 170.

, from the Pole to the Equator, i.

189.

ravages caused by

— , section of debris deposited by
opposing, i. 378.

, causes and velocity of, i. 382. 385.
, destroying and transporting power
of, i. 392. ; ii. 30. 32. 34.
•, in estuaries, their power, i. 400.
•, in the Straits of Gibraltar, ii. 14.
-, reproductive effects of, ii. 22.
, on the British shores, ii. 22.

, distribution of drift-timber by, iii.

225.

Curtis, Mr., on

aphides, iii. 93.
Curtis, Mr. John, on power of the ti-

pula? to cross the sea, iii. 67.

, @n number of British insects, iii .
148.

, on fossil insects, iii. 229. ; iv. 211.
Curves of the Mississippi, i. 283.
Cussac, fossils in alluvium under lava
at, iv. 136.

Cutch, changes caused by earthquake of
1819 in, ii. 194. ; iii. 253. 435. ; iv. 174.
253.285.

, map of ( see plate 5. ), ii. 194. .
Cuvier, on durability of bones of men,

i. 246. ; iii. 245.

■ , on variability in species, ii. 391. 394.

, on identity of Egyptian mummies
with living species, ii. 397.

■, on number of fishes, iii. 149.

■, on extinction of the dodo, iii. 113.

-, on oolite fossils, i. 237. ; iv. 310.

, on mammiferous remains of the
Upper Val d'Arno, iv. 138.

-, on tertiary strata of Paris basin,

iii. 332. ; iv. 166. 172 179.
Cuvier, M. F., on aptitude of some ani-
mals to domestication, ii. 408.
., on influence of domestication, H.

413.
Cyclops, island of, in bay of Trezza, iii.

401.
Cypris, fossil, iii. 262.; iv.. 150. 282.

, habits of living species of ( see

figs.), iv. 150.

VOL. IV.

410

INDEX.

■

Dalman, M., on greywacke rocks of

Sweden, iv. 300.
Danger field, Captain F., on buried cities

in Central India, iii. 194.
Daniel!, Professor, on the trade- winds,

i. 188.
., on melting point of iron, ii. 314.

., on fusion of metals, ii. 317.

., on deoxidating power of hydrogen,

ii. 328.
Danish Archipelago, undermined by

currents, ii. 12.
Dante, embankment of rivers noticed

by, i. 281.
Dantzic, waste of land near, ii. 12.
D'Anville, M., on gain of land in Red

Sea, ii. 28.
Darby on drift-wood of Mississippi, i.286.
., on lakes formed by Red River, i.

290.

— , on marine strata of Lower Louis-
iana, i. 291.
., on delta of Mississippi, i. 365.
Darent, transverse valley of the, iv. 238.
Dartmoor granite, iv. 368.
Daubeny, Dr. on mineral springs, i. 309.
. on country round the Dead Sea, i.

331.

, on Mount Vultur, ii. 57.

— , on decomposition of trachyte, ii.

90. ; iv. 374.

, on flowing of lava under water, ii.

94.
- oh vicinity of volcanos to the sea,

Davy, Sir H., his theory of progressive

development, i. 227.

, on eruption of Vesuvius, ii. 85.
— , on chemical agency of electricity,

ii. 323.
., his theory of an unoxidated me-

tallic nucleus, ii. 327.
, on agency of air and water in vol-

canos, ii. 349. 351.
-, his analysis of peat, iii. 177-

ii. 347.

■, on agency of air and water in vol-
canos, ii. 349. 351.

., on nitrogen in mineraLsprings, iii.

158.
., on Val di Noto limestone, iii. 387.

., on eruption of Vesuvius in 1834,

iii. 424.
. on volcanic region of Olot, iv. 91.
on volcanic district of Lower
Rhine and Eifel, iv. 113.
_ on Auvergne volcanos, iv. 200.

D'Aubuuson cited, i. 103.; iii. 422.
Daun, lake-craters near, iv. 104.
Davis, Mr., on the Chinese deluge, i.

11.
Davy, Sir FT., on lake of the Solfatara,

i i 320.

., on formation of travertin, i.321.

Davy, Dr., on Graham Island, ii. 152-

348.
., on a helmet taken up from the sea

near Corfu, iii. 251.
Davy, Rev. C, on Lisbon earthquake,

ii. 352.
Dax, tertiary formations of, iii. 338. ;

iv. 119.

, inland cliff near, iv. 124.

Dead Sea, waters of, i. 331. .

. , the country around it volcanic, I.

331. ; ii. 54.
De Candolle on hybrid plants, ii. 431-
., on distribution of plants, iii. 4, 5-

7. f

., on agency of man in dispersion or

plants, iii. 22.

, on stations of plants, iii. 87-

., on the barriers which separate dis-
tinct botanical provinces, iii. 144.
, on number of land plants, iii. 148-
,, on longevity of trees, iii. 428.
Dee, R., bridge over, swept away W

floods, i. 267. # „

Deer, their powers of swimming, iii. *>•
, formerly abundant in Scotland,

iii. 110.
, remains of, in marl lakes, in. 2J&;

Deguer on remains of ships, &c ' n

Dutch peat-mosses, iii. 187.
De la Beche, Mr., on greywacke fossils,

i.201. „ r _
, on delta of Rhone in Lake of ge-
neva, i. 338.

, on storm of Nov. 1824, i. 429.

., on earthquake of Jamaica, 1692,

ii. 263.
., on action of rain in the tropics,

iii. 165.
., on drifting of plants to sea d.

hurricanes, iii. 225.

, on coral formations, iii. 288.

., on alternation of coral and lava i
Isle of France, iii. 294. .

., on fossil forest of I. of Portland,

iv. 285.

^r"

INDEX.

411

De la Beche, Mr., on granite of Dart-
moor, iv. 368.

Be la Hire on fossil wood from Ava

1692, i. 49.
Delhi territory, elephants in, i. 152.
Delille on wheat in Egyptian tombs,
ii. 398.

on native country of wheat, ii.

399.
Delta of the Adige, i. 350.

of the Brenta, i. 350. \

of the Burrampooter, i. 358.

of the Ganges, i. 358.

, its stratification, i. 376. '

of the Isonzo, i. 350. .

of the Mississippi, i. 364*. 376.

of the Niger, size of, iv. 309.

of the Nile, i. 353. ; iii. 348.

of the Po, i. 350.

— of Rhone, in Lake of Geneva, i.
337. ; iii. 346.

— of Rhone, in Mediterranean, i.

346.

of the Tagliamento, i. 350.

Deltas, chronological computations of

age of, i. 339.
., of Lake Superior, i. 342.

., of the Baltic, i. 344.

, oceanic, i. 357.

, grouping of strata in, i. 371.

., independent in same basin, i. 373.
De Luc, his treatise on geology, 1809,
i. 99.

, on origin of granite, i. 102.

— , on age of deltas, i. 342.
, on conversion of forests into peat-
mosses, iii. 181.
, on the deluge, iv. 203.

De Luc, M. G. A., his natural chrono-
meters, iii. 188.

Deluge, ancient theories on causes of,
i. 32. 46. 53. 55. 57, 58. 60. 74.
., fossil shells referred to the, i. 34.

57.
., on changes caused by the, iv. 201.

„ M. de Beaumont on cause of his-
torical, iv. 218.
Deluges part of the present course of
Nature, i. 133.
., local, how caused, i. 10. 292.
., traditions of different, i. 10. 21.74. ;
ii. 52.
Demaillet, speculative views of, ii. 373.
Denmark, tertiary strata of, iv. 87.
Denodur volcano, ii. 195.
Denudation, effects of, iii. 165. 349. 352.

T 2

Denudation of valley of the Weald,iv.221 .
Deposition of sediment, rate at which

the finer kinds subside, ii. 34.
-, shifting of the areas of, iii. 345.
Derbyshire, Whitehurst on, i. 79.
Descartes, iii. 426.
Desha^es, M., on fossil shells, iii. 339

369. 374. 387. 402. ; iv. 23. 28. 71. 131. '

141. 175. 272. 279. 327.

, on subdivisions of the tertiary

strata, iii, 366.

•, on limestone of Blaye, iv. 122.
Desjardin, M., bones of the dodo found

under lava by, iii. 113.
Desmarest considered geology a branch

of physical geography, i. 5.
, on Auvergne, i. 86.

, on the separation of England from

France, i. 420.

Desmoulins, M. Ch., on Eocene depo-
sits near Bordeaux, iv. 123.

, on fossils of S. of France, iv 259

Desnoyers, M., on human remains
caves, iii. 215.

— , on tertiary formations of Touraine
iii. 338. 366. ; iv. 115. 117. ' '

,on fossils of the Orleannais, iv. 137.
on alternation of plastic clay and
calcaire grossier in Paris basin, iv. 168.
, on the Cotentin, iv. 208.
Deucalion's deluge, i. 21.
Diceras limestone, iv. 289.
Didelphis, fossil, in oolite, i. 237.
Dikes, composition and position of.
85. ; iii. 390. 392. 417. 421.'; iv. 5. 24.
how caused, iii. 85. ; iv. 6.

, changes caused by, iii. 392. 417 • iv
364. 378.

Diluvial theories, iv. 201.

waves, whether there are signs of
their occurrence on Etna, iii. 43i #
, no signs of in Campania, iv. 14.
Dimlington height, waste of, i. 4Q2.
Diodorus Siculus cited, ii. 53. 115.
Dion Cassius cited, ii. 68.
Dodo, recent extinction of the, iii. ]]2,
Dog, varieties of the, ii. 367. 393.
, its distinctness from the wolf.

11.

394.

11.

, hybrids between wolf and, ii. 424.

, examples of acquired instincts he-
reditary in the, ii. 409.

has run wild in America, iii. 115.

Doggerbank, Capt. He wet* on the ii

30.

Dollart, formation of estuary of the ii,*\

Ittf.

MHI

412

INDEX.

Dolomieu on the Val di Noto, Vicentin,

and Tyrol, i. 87.

on lavas of Etna, i. 87.

on decomposition of granite, i. 333.

on earthquake of 1783^in Calabria,

ii. 213. 215. 229. 242.

Domestication, aptitude possessed by
some animals to, ii. 408. 419.

, influence of, ii. 413.

Dominica, coral between two lava cur-
rents in, iii. 294. ; iv. 22.

Don, R., transportation of rocks by, i.

267.
Donati on bed of Adriatic, i. 68. 127.

351. ; iii. 272. j

D'Orbigny cited, iv. 176.
Dorsetshire, landslip in, i. 427.

, waste of cliffs of, i. 429.

, valleys of elevation in, iv. 249.

Doue, M. Bertrand de, on tertiary strata

of Velay, iv. 136. 157, 158. 190.

, on Auvergne alluviums, iv. 197.

Dover, waste of chalk cliffs of, i. 419.

, depth of sea near, i. 420.

, formation of Straits of, i. 420.
, strata at foot of cliffs of, i. 422. ; iv.

261.
Downham buried by blown sand, iii. 191.

Dranse, R., i. 295. 297.

Drift-sand of African deserts, iii. 188.

Drift-wood of Mississippi, i. 284. 287*

365.

, imbedding of, iii. 219.

., , abundant in North Sea, iii. 224.

Drinkwater, Mr., i. 100.

Drongs, granitic rocks of Shetland, worn

by the sea, i. 397.
Drontheim, ii. 302.
Druids, their doctrines, i. 27.
Du Bois, M., on tertiary strata of Vol-

hynia and Podolia, iv. 132. .
Dufrenoy, M., on the Pyrenees, i. 211. ;

iv. 368.
., on tertiary strata of S. of France,

iv. 119. 121. 124.

on limestone of Blaye, iv. 123.
! 9 on hill of Gergovia, iv. 186.
on age of red marl and rock-salt of

Cardona, iv. 316.

. , on chalk of S. of France, iv. 276.

Dujardin, M., on shells, &c. brought up

by artesian well at Tours, i. 307-
., on foraminifera of Paris basin, iv.

176.
Dunes, hills of blown sand, i. 404. ; n.

k 21. ; iv. 81.;

• •

Dunwich, destroyed by the sea, i. 411.

, crag strata in cliffs near, iv. 77. 79.

Durance, R.. land-shells drifted by the,

iii. 360.
Dureau de la Malle, M., cited, ii. 396.

408.
Durham, waste of coast of, i. 402.

Earth, antiquity of the, i. 35.

., on changes in its axis, i. 53. 57.
., proportion of land and sea on its

surface, i. 221.

., spheroidal form of the, ii. 309.

., mean density of the, ii. 311.

., electric currents in the, ii. 324.
— , sections of the {see Jigs. 59, 60.,, "

316. 333.
., effects produced by the powers ot

vitality on its surface, iii. 153.

Earth's crust, signs of a succession of for-
mer changes recognizable in, iii. 303.
, arrangement of materials com-
posing the, iii. 311.

Earthquakes, energy of, probably uni-
form, i. 94. 132.

., earth's surface continually re-
modelled by, i. 181.
— , all countries liable to slight shocks

of, ii. 59.

chronologically described, see Vol.

II. p. 181. et seq.

— , phenomena attending, ii. 182.
_-, in Cutch, 1819, see map, ii. 194.
..-, in Calabria, 1783, ii. 210.
., difficulty of measuring the effects

of, ii. 217.

, chasms formed by, ii. 224, 935- ^
., excavation of valleys aided by, IU

237. ; iii. 442.
., renovating effects of, ii. 3o3. 3j»-
., cause of the wave-like motion oU

11. ooo. .-

, cause of retreat of sea during, 1U

254. . ...

, ravages caused by sea during, »*•

198. d

., several thousand people entomoe

in caverns during, iii. 207.
. their effects in imbedding citie»

and forests, iii. 252.
., in the Pacific, iii. 296.

9 causes of volcanos and, ii. 307.

East Indian Archipelago, tertiary form-
ations of, iv. 23.

INDEX.

413

Ecchellensis, Abraham, i. 23.

Edmonstone Island, i. 360.

Edwards, Mr. M., on corals of the crag,

iv. 73.
Eels, migrations of, iii. 53.
Egerton, Rev. Mr., on delta of the Kan-

der, iv. 69.
Egypt, nearly exempt from earthquakes,

i. 14. ; ii. 57.
, cities and towns buried under drift-
sand in, iii. 188. 190.
Egyptian cosmogony, i. 12. 249.
mummies identical with species

still living, ii. 395.
Ehrenberg, M. C. G., found Bengal tiger

in Siberia, i. 147.
on corals of Red Sea, iii. 275. 283.

288. 293. 359.
Ehrenhausen, coralline limestone of, iv.

130.
Eichwald, M., on tertiary deposits of

Volhynia and Podolia, iv. 132.
Eifel, volcanos of the, iv. 101.

, lake-craters of the, iv. 102.

• ., trass of the, and its origin, iv. 108.

Electricity, a source of volcanic heat,

ii. 323.

. , whence derived, ii. 326.

Elephant, fossil, in ice on shores of

North Sea, i. 80. 151.
* Elephant Bed' at Brighton, i. 422. ; iv.

261. 267.
Elephants covered with hair in Delhi, i.

152.

., their sagacity not attributable to
their intercourse with man, ii. 418.
,, their powers of swimming, iii. 33.
Elevation of land, how caused, i. 50. ;

ii. 184. 189. 256. 339. ; iii. 436.

, proofs of successive, iii. 440.

Elevation and subsidence, proportion of,

ii. 355.
Elevation craters, Von Buch's theory

of, considered, ii. 152.
Elevation valleys, ii. 176. ; iv. 246. '
Elizabeth or Henderson's Island de-
scribed, iii. 295.
Elsa, travertin formed by the, i. 312.
., freshwater formations of the, iv.

27.

Embankment, system of, in Italy, i.

280.
, gain of land in Adriatic more rapid

in consequence of, i. 351.

Emu in Australia will become extermi.

nated, iii. 112.

Engelhardt on the Caspian Sea, ii. 51 -

iii. 126.
England, waste of cliffs on coast of, i .

402.

•, slight shocks of earthquakes felt
in, ii. 59.

— , height of tides on east coast of, i.
381. 409.

, tertiary strata of, iii. 335, 336. ; iv.

25. 71. 211.

■, excavation of valleys in S.E. of, iv.

263.

, geological map of S.E. of, iv. 221.

Eocene period, derivation of the term,
iii. 370.
>, fossils of the, iii. 371. 373.
, freshwater formations of, iv. 143.
, marine formations of, iv. 164.
, physical geography, fauna and
flora of the, iv. 181.
■— , volcanic rocks of, iv. 184.

, map of principal tertiary basins of,
iv. 209.

-, alluviums of, iv. 263.
•, chasm between secondary form-
ations and those of, iv. 279.

., hypogene rocks formed since, iv.
389.
Epomeo, Monte, height, &c, iv. 11.

, shells in tuff near summit of, iv.12.
Equatorial current, i. 170.
Equinoxes, precession of the, i. 178.

Erhebungscratere, theory of, considered,
ii. 152.

Erie, lake, rapidly filling up, i. 278.

, peninsula cut through by, ii. 11.

Erman, M., on specific gravity of sea.

water,], 172.
, on level of Caspian, iii. 126. ; iv.

203.
Erratic blocks of the Alps, iv. 46.

, transported by ice, i. 269. ; iv. 48.
Eruptions, volcanic, number of, per

year, ii. 178.

• , cause of, ii. 307. 341.

Er2gebirge, mica slate of the, i. 84.
Escarpments, manner in which sea de-
stroys successive lines of, iii. 440. ; iv.

229.
of chalk in Weald valley, once

sea cliffs, iv. 227, 228.
Escher, M., on flood in valley of Bagnes,

i. 296.
Eschscholtz Bay, fossils of, i. 153.
Escrinet, Pass of, conglomerate forming

at, iii. 210. ,

414

INDEX.

Essex, inroads of sea on coast of, i. 415.
Estuary „, deposits, arrangement of, iii.

312.
Estuaries described, i. 401.

., new ones in Holland, ii. 7.
., how formed, ii. 23.
, tides in, ii. 24.

., gain of land in, does not compen-
sate loss of coast, ii. 25.
, imbedding of freshwater species

in, iii. 262.

Eternity of the earth, or of present sys-
tem of changes, not assumed in this
work, iv. 392.

Etna, description of, ii. 71. 111. 5 iii-

397. 407. 421.

., lavas of, i. 272. 371. ; ii. 175.

, minor volcanos on, ii. 113.
— , buried cones on flanks of, ii. 114. ;

iii. 415.
., eruptions of, ii. 115. 120. ; iii. 413.
., towns overflowed by lava of, ii.

118. ; iii. 193.

— , subterranean caverns on, ii. 120.

., great floods on, ii. 123.

., glacier under lava on, ii. 124.

., its cone truncated in 1444, ii. 167.

, marine formations at its base, ii.

158. ; iii. 397. 401.
., great valley on east side of, iii. 407.
, form, composition, and origin of

the dikes on, iii. 417.
., subsidences on, iii. 424.
., antiquity of cone of, iii. 426.
-, whether signs of diluvial waves are

observable on, iii. 431.
Euganean Hills, lavas of, ii. 60.
Europe, newest tertiary strata of, iii.

339.
, geological map of {see plate 2.), i.

214.
., large portions of, submerged when

secondary strata formed, iii. 341.

European tertiary strata, successive

origin of, iii. 335.

European alluviums in great part ter-
tiary, iv. 45.

Euxine burst its barrier, according to

Strabo, i. 25.
, gradually filling up, i. 25.

, see Black Sea.

Evaporation, quantity of water carried

off by, i. 350. 386. ; ii. 14.

, currents caused by, i. 386.

Everest, Mr., on island of Munkholm,

ii. 302.

Everest, Rev. R., on climate of fossil

elephant, i. 152.

, on sediment of Ganges, i. 367.

Excavation of valleys, ii. 237. ; iv. 263.
Extinction of species, successive, part of

the economy of nature, iii. 134. 142.
Eyderstede overwhelmed by sea, ii. 13.

Fabio Colonna, i. 39.

Facial angle, ii. 437.

Fair Island, action of the sea on, i. 399.

Falconi on elevation of coast of Bay ot

Baia?, ii. 281.
Falloppio on fossils, i. 36.
Falls of Niagara, i. 275.

of St. Mary, i. 343.

Faluns of Touraine, iv. 115.

, compared to the English crag, iv.

116, 117.
., how formed, iv. 117.

., fossils of, iv. 116. 119.
Faraday, Mr., on water of the Geysers,

i. 328.
-, on slow deposition of sulphate ot

baryta powder, ii. 35.
•, on electric currents in the earth,

ii. 325.
-, on metallic reduction by voltaic

agency, ii. 328.
., on liquefaction of gases, ii. 337.

., experiments of, on carbonate of

lime, iv. 366.
Faroe Islands, deposits forming near the*

iii. 272.

Farquh arson, Rev. J., on floods in Scot-
land, i. 267.

Fasano, marine strata near, iii. 401.

Faujas, on Velay and Vivarais, 1779,

i. 86.
Ferishta, i. 9.
Ferrara on lavas of Etna, i. 371.

on floods on Etna, ii.124.

on earthquake in Sicily, ii. 208.
Ferruginous springs, i. 330.
Ferussac on distribution of testacea,

iii. 56.
Fetlar, effect of lightning on rocks of,

i. 394.
Fez, earthquakes in, ii. 57.
Fife, coast of, submarine forests on,

i. 401.
., encroachments of sea on, i. 401.

Findhorn, town swept away by sea*
i. 39a

INDEX.

415

Finochio, rock of, iii. 420.
Firestone of Weald valley, iv. 222.

, terrace formed by, iv. 229.

Fish, their geographical distribution,

iii. 52.

, migrations of, iii. 53.

, fossil, i. 235. ; iii. 272. 358. ; iv.

292. 296.
Fissures, sulphur, &c. ejected by, ii. 209.
caused by earthquake of 1783 in

Calabria, ii. 218. 222. 225.
, cause of the opening and closing

of, ii. 262.
., preservation of organic remains in,

iii. 201.
Fitton, Dr., on history of English geo-
logy, i. 73.

., on valley of the Weald, iv. 222.
225. 231. 252. 281, 282. 284.
— , on a line of vertical and inclined
strata from I. of Wight to Boulogne,

iv. 260.
., on Maestricht beds, iv. 272. 274.

., on delta of Niger, iv. 309.

FitzRoy, Capt, on earthquake in Chili,

1835, ii. 185. 187. 192.
Fiume Salso, in Sicily, iv. 178.
Flagstones and slates, difference be.

tween, iv. 356.

Flamborough Head washed into caves,

i. 402.
Fleming, Dr., on uniformity in climate,

i. 140.

, on food of fossil elephant, i. 146.
— , on submarine forests, i. 401. j iii.

227.
, on rapid flight of birds, iii. 48.

., on turtles taken on coast of Eng-
land, iii. 50.

on changes in the animal king-
dom caused by man, iii. 109.
., on stranding of cetacea, iii. 266.
., on fossils of the crag, iv. 73.
., on effects of the deluge, iv. 204.
Flinders on coral reefs, iii. 275. 280.

291.
Flint on course of Mississippi, &c., i.

282. 285.

on earthquakes in Mississippi val-
ley, ii. 204.

Flood, supposed effects of the, iv. 201.

., hypothesis of a partial, iv. 201.

Floods, bursting of lakes, &c, i. 292.

in North America, i. 293.

in valley of Bagnes, i. 295.

in Scotland, i. 266. ; iii. 233.

Floods at Tivoli, i. 298.

— on Etna, ii. 123.

Floridia, limestone of, iii. 387.

Fluvia, R., ravines in lava excavated

by, iv. 93. 97.
Foah, advance of delta of Nile near, i.

354.

Folkestone, subsidence of land at, i. 422.
Fontenelle, his eulogy on Palissy, i. 39.
Foraminifera of the crag, iv. 75.

of the Paris basin, iv. 176.

Forbes, Mr., on Bay of Baia>, ii. 277.

, on temple of Serapis, ii. 279.

Forchhammer, Dr., on tertiary strata of

Denmark, iv. 88.
Forest ridge of Weald valley, iv. 231.

, faults in strata of the, iv. 231.

, thickness of masses removed from

the, iv. 259.
Forests, influence of, iii. 163. 165. 168.

, sites of, now covered by peat, iii.

180.

, destroyed by insects, iii. 173.

, submarine, i. 400. ; iii. 226.

Forfarshire, encroachments of sea on
coast of, i. 400.

, marl lakes of, iii. 259. 300. '

, composition of secondary rocks of,

iv. 377.

Forio, earthquake near, ii. 188. .

Formosa, earthquakes in, ii. 48.

Forster, Mr., on coral reefs, iii. 275.

Forsyth on climate of Italy, ii. 110.

Fortis on Arabian doctrine of new ge-
nera and species, i. 24.

, views of Arduino confirmed by, i.

85.

— — and Testa on fossil fish of Monte

Bolca, i. 78.
Fossa Grande, section of Vesuvius seen

in, iii. 410.
Fossilization of organic remains on
emerged land, iii. 177.

in peat mosses, iii. 182.

in caves and fissures, iii. 201.

in alluvium and landslips, iii. 197.

in volcanic formations on land, iii.

191.

— in subaqueous deposits, iii. 218.

238.

— by river floods, iii. 231.

in marl lakes, iii. 236.
of plants , and animals partial, iii.

350.

Fossils, speculations concerning their
nature, i. 42. 45. 47.

416

INDEX.

Fossils, formerly all referred to the
deluge, i. 43.

of the coal strata, i. 158. 201. 231.

, distinctness of secondary and ter-
tiary, i. 211. - 3 iv. 279.

, mammiferous, of successive ter-
tiary eras, iii. 379.

. See Organic Remains.

Fourier, Baron, on temperature of
spaces surrounding our atmosphere, i.
192.

, on central heat, i. 222.

, on radiation of heat, i. 223.

Fournet, M., on alluvium in ancient
fissures, iv. 198.

. , on disintegration of rocks, iv. 373.

. , on mineral veins, iv. 375.

Fox, Mr., on heat in mines, ii. 313.

, on electric currents in the earth,

ii. 324.

France, waste of coast of, i. 431.

, caves of, iii. 213.

Franconia, caves of, iii. 210.

Frankfort, tertiary strata near, iv. 132.

Franklin on a whirlwind in Maryland,
iii. 11.

Freshwater formations, species of tes-
tacea few in, iii. 265.

. , secondary, why rare, iv. 314.

Freshwater plants and animals fossil-
ized, iii. 258. 262.

Freyberg, school of, i. 81. 92.

Freyer, Mr., on earthquake in Chili, ii.

191.

, on Isle of San Lorenzo, iv. 17.

Fries on dispersion of cryptogamic

plants, iii. 13.
Frisi on influence of vegetation, iii.

163.
Fuchsel, opinions of, 1762, i. 76.

Funchal, rise of sea during earthquake

at, ii. 254.

Fuveau, in Provence, tertiary strata of,
iv. 210.

Gabel Tor, volcano of, ii. 58. ; iv. 26.
Galieri, a bed of corals among igneous

formations at, iii. 396.
Gambier coral island, iii. 290.
Ganges, delta of the, i. 358. 376.
•, its ancient mouths, i. 358.
, inundations of the, i. 363. 5 iii.
234,

Ganges, quantity of sediment in waters
of, i. 367.

and Burrampooter not yet com-
pletely united, i. 376.

, islands formed by the, iii. 170.

, bones of men found in delta of, iii*

245.

Gannat, freshwater limestone of, iv.

152.
Gardner on destruction of Dunwich by

the sea, i. 412.
Gardner, Mr., cited, i. 177. 221.
Garnets, in altered shale, iv. 365.
Garrinada, hill of, iv. 93.
Gases, liquefaction of, ii. 337.

, evolved by vol can os, ii. 348.

, passage of, through rocks, iv. 372.

Gaulish Druids, i. 27.

Gault of Weald valley, iv. 222.

, valley formed at its out- crop, iv.

230. ■ ,

Gavarnie, cirque of, iii. 415.
— , lamination of clay-slate near, iv.

362.
Gay-Lussac, M., on the vibration of

solid bodies, ii. 337-
., on agency of water in volcanos, ii.

348.
Gefle, upraised shelly deposit near, ii.

298. 301.
Gemmellaro on eruption of Etna in

1811, ii. 121.

on ice under lava, ii. 124.

Gemunder Maar, view of, iv. 104.

Generation, spontaneous, theory of, i.

38.
Generelli, on state of geology in Europe

in middle of 18th century, i. 62.
, on effects of earthquakes in recent

times, i. 65, 66. 93.
Geneva, lake of, men drowned above

Martigny floated into, i. 296.

, delta of Rhone in, i. 337. 372. ; iii.

347.
Genoa, tertiary strata at, iv. 63.

Geognosy of Werner, i. 81.

Geographical distribution of plants, iii.

of animals, iii. 27.

of birds, iii. 45.
of reptiles, iii. 49.
of fishes, iii. 52.
of testacea, iii. 55.
of zoophytes, iii. 61.
- of insects, iii. 62.
of man, iii. 68.

INDEX.

417

Geography, proofs of former changes in

physical, i. 199. 214.
., effect of changes in, on species, ill.

122.
Geological Society of London, i. 104.
Geological theories, causes of error in

i. 110.
Geology defined, i. 1.
compared to history, i. 1.

its relation to other physical
sciences, i. 2.
— distinct from cosmogony, i. 5.

considered by Werner as part of
mineralogy, i. 5.

., causes of its retardation, i. 42. 97.
110.

., state of, in Europe, before middle
of last century, i. 63.

., modern progress of, i. 104.

Georges Gemund, freshwater strata of,
iv. 133.

Georgia, in island of, perpetual snow to
level of sea, i. 175. 193.

Gerbanites, an Arabian sect, their doc-
trines, i. 24.

Gergovia, section of hill of, iv. 186.

German Ocean, filling up, ii. 29.

Gesner, John, on organic remains, i. 71.

Geysers of Iceland, i. 328. ; ii. 342.

■, cause of their intermittent action,

ii. 344.

Giacomo, St., valley of, described, iii.
411, 412. 419.

Gian Greco, fall of cliffs during earth-
quake, ii. 236.

Gibbon cited, i. 120.

Gibraltar, birds' bones in breccia at, iii.

209.
, Straits of, ii. 14.

J t supposed under-current in, ii. 15.

Gillenfeld, Pulvermaar of, iv. 105.
Girard, M., on mud of the Nile, i. 355.

9 on former union of Mediterranean

and Red Sea, ii. 31.
Girgenti, tertiary strata at, iii. 385.
Gironde, tides in its estuary, ii. 24.

, tertiary strata of basin of, iv. 119.

Glacier, under lava, on Etna, ii. 124.
Glaciers, formation of, i. 156. 269.

of Spitzbergen, i. 172.

., transportation of rocks by, i. 269. ;

iv. 47.
Glen Roy, parallel roads of, iv. 18.

Glen Tilt, granite veins of, i. 90.

, junction of limestone and granite

in, iv. 340.

Gloger, M., cited, iii. 75.
Gloucestershire, gain of land in, i. 430.
Gly, R., tertiary strata in valley of the,

iv. 69.
Gmelin on distribution of fish, iii. 54.

Gneiss, mineral composition of, iv. 361.
363.

■, passage of, into granite, iv. 363.

371.

, whence derived, iv. 363. 375.

Goats, multiplication of, in South Ame-
rica, iii. 115.

Godman on migrations of rein-deer, iii.
41.

Goebel, Mr., on level of Caspian, iv.

203.

Golden age, doctrine whence derived, i.
13.

Goldfuss, Professor, on the greywack£,
iv. 299.

Goodwin Sands, i. 418.
Goree on new island, ii. 163.
Gothenburg, rise of land near, ii. 297.
Gozzo degli Martiri, dikes at, iii. 390.

, view of valley of, iii. 439.

Graah, Capt., on subsidence of Green-
land, ii. 302. ,

Graham, Mrs., on earthquake of Chili

in 1822, ii. 190.
Graham Island, ii. 146. ; iii. 393.

, views of, see wood-cuts, ii. 147,

148, 149.

, depth of sea from which it rose, ii.
146.

, arrangement of the ejected ma-
terials on, ii. 148.

Grammichele, strata near, iii. 387.

, bones of mammoth in alluvium at,

iv. 48.

Grampians, granite veins of the, iv. 342.
Granada, tertiary strata of, iv. 70.
Granite of the Hartz, greywacke slate

with organic remains found in, i. 84.
, disintegration of, in Auvergne, i,

333.

, junction of limestone and, in Glen
Tilt, iv. 340.

, formed at different periods, iii.
317. ; iv. 343.

348.
, origin of, iii. 316.,; iv. 350„
, passage of gneiss into, iv. 363. 371.
, changes produced by its contact

with strata of lias and oolite in the
Alps, iv. 369.

Granite veins, their various forms and

418

INDEX.

mineral composition, i. 90.;
63.

IV. COO*

Graves, Lieut., on diffusion of insects

by the wind, iii. 66.

Graves, Mr., on distribution of the bus-
tard, iii. 111. .

Graves, M , on Valley of Bray, iv. 28/.

Gravesend, indentations in chalk filled
with sand, &c, near, iv. 217.

Grecian Archipelago, new isles of the,

i. /6.
., volcanos of the, ii. 58.

., chart and section of, ii. 161.
Greece, earthquakes in, iii. 207.
Greenland, why colder than Lapland,!

168.

, earthquakes in, ii. 58.
, gradual subsidence of, ii. 302. 340.
timber drifted to shores of, iii.

Gulholmen, island of, gradually rising,

ii. 297.
Gun-barrel, with shells attached, found

in sands, iii. 250.
Gunnell, Mr., on loss of land in Sheppey,

i. 415.
Gypsum and marls of Paris basin, iv.

171.
, bones of quadrupeds, &c, in, **•

177.
, of St. Romain on the Allier, iv.

154.
■, Subapennine, iv. 54.
Gyrogonite described, iii. 259.

224.
Greenough, Mr., on fossil shells from

borders of Red Sea, iv. 26.
Greville, Dr., on drift sea- weed, iii. 16.
Greywacke formations, fossils of, i. 2C0.

232. ; iv. 297.
of the Eifel, iv. 102.

, classification of the, iv. 298.

Grffone, Monte, caves in, iv. 41.

Grimaldi on earthquake of 1783 in Ca-
labria, ii. 212. 225. 228.

Grind of the Navir, passage forced by
sea in Shetland Islands, i. 396.

Grosceil tertiary strata at, iv. 24.

Grosse, Dr., on baths of San Filippo, i.

316.
Grotto del Cane, i. 332.
Gryphyte limestone, iv. 291.
Guadaloupe, human skeletons of, iii.

245.

, volcanos in, iv. 22.

Guatimala, active volcanos in, ii. 45.

, town of, swallowed up by earth-

quakes; ii. 248.
Guettard, on the Vivarais, i. 86.
Guiana, its maritime district formed by
sediment of the Amazon, ii. 33.

Guidotti, Signor, on Subapennine fossils,

iii. 364.
, on shells in gypsum of Monte

Cerio, iv. 54.
Guilding, Rev. L., on migration of boa

constrictor, iii. 51.
Guinea current, i. 383.
Guldenstadt on distinctness of the dog

and wolf, ii. 394.

Gulf stream, i. 170. 384. 391. ; iii. *4.

Habitations of plants described, iii. 5.
Hall, Sir J., his experiments on rocks,

i. 90. ; iv. 9.
Hall, Capt. B., on Falls of Niagara, L

275.

, on width of Mississippi, i. 282.

., on islands in Mississippi, i. 284.
*, on drift-wood in Mississippi, i. 287.

365.
, on flood in valley of Bagnes, i.

296.

— , on the trade winds, i. 389,

•, on volcanic eruption in Tierra del

Fuego, ii. 41.

, on temple of Serapis, ii. 274,

., on isle of Cyclops, iii. 403.

. on parallel roads of Coquimbo, iv

18.

, on dikes in Madeira, iv. 24.

., on veins in the Table Mountain,
Cape of Good Hope, iv. 339.
Hall, Mr. J., on temple of Serapis, ii-

274.
Hallstrom, Col., on rise of land in Gult

of Bothnia, ii. 291.
Hamilton, Sir W., on mass covering

Herculaneum, ii. 99.

-, on earthquake of 1783, in Cala-
bria, ii. 213. 229. 232.

, on earthquakes attending eruption

of Monte Nuovo, ii. 281.
i, on eruption of Vesuvius in 1779,

ii. 82. 174. ; iv. 7.
Hamilton, Sir Charles, on submerged

buildings of Port Royal, iii. 255.
Hampshire, Brander on fossils of, i- 77.
, submarine forest on coast of, « J

227.

■

INDEX.

419

Hampshire, tertiary formations of, iii.
335.; iv. 211. 215.

, on former continuity of the basins

of London and, iv. 219.
Happisborough, crag strata near, iv. 79.
Harcourt, Rev. W. V. V., on bones of

mammoth, &c. in Yorkshire, i. 145.
Harlbucht bay, ii. 8.
Harris, Hon. C, on sunk vessel off

Poole harbour, iii. 246.
— -, on a submarine forest on coast of

Hampshire, iii. 228.
Hartmann, Dr., on grey wacke fossils in

granite of the Hartz, i. 84.
Hartsoeker on sediment in waters of

Rhine, i. 366.
Hartz mountains, i. 84. ; iv. 332.
Harwich, waste of cliffs at, i. 415.
Hastings sands, their composition, iv.

222.

, anticlinal axis formed by, iv. 225.

Hatfield moss, trees found in, iii. 180.
Haute Loire, freshwater formation, iv.

157.
Headen Hill, section of, iv. 216.

Heat, laws which govern the diffusion

of, i. 166.
, its influence on consolidation of

strata, iv. 317.
Heber, Bishop, on animals inhabiting

the Himalaya mountains, i. 152.
Hebrides, volcanic rocks of the, iv.

319.
Hecla, columnar basalt of, i. 85.
— , eruptions of, ii. 126.
Heidelberg, loess and gravel alternating

at, iv. 31.

granites of different ages near, iv.

42.

Helice and Bura, submerged Grecian

towns, ii. 56. ', iii. 255.
Heligoland destroyed by sea, ii. 7.
Helix, range of species of, iii. 57.
Helmet, changes of submerged, iii. 251.
Henderson on eruption of Skaptar Jokul,

1783, ii. 127.
Henderson's Island described, iii. 295.

Henry, Mr., on absorption of carbonic

acid by water, i v. 372.

Henslow, Rev. Prof., on the cowslip, ii.

403.

on diffusion of plants, iii. 19.

i on changes caused by a dike in
Anglesea, iv. 364. 378.
Herbert, Hon. Mr., on varieties and
hybrids in plants, ii. 403. 431.

Herculaneum, silence of contemporary

historians concerning, ii. 67.
how destroyed, ii. 94.
, objects preserved in, ii. 100.
, stalactite formed in galleries of, ii.

101.
Heme Bay, waste of cliffs in, i. 416.
Herodotus cited, i. 353. 355.
Herschel, Sir J., on annual quantity of

light and heat received by the two

hemispheres, i. 178.
, on the sun, i. 224.

•, on astronomical causes of changes
in climate, i. 224.

— , on the trade winds, i. 391.
— , on height of Etna, ii. 111.
, on form of the earth, ii. 309.
•, on Geysers of Iceland, ii. 344.
, on the effects of heat on seeds,iii,14.
, on cleavage planes, iv. 358.
Herschel, Sir W., on the elementary

matter of the earth, ii. 308.
Hewett, Capt., on rise of tides, i. 382.

, on currents, i. 385.

, on banks in North Sea, ii. 29.

Hibbert, Dr., on the Shetland Islands,
i. 393. 395. 397.

^, on Rhine volcanos, iv. 106.

., on loess of the Rhine, iv. 34. 38.

, on fossils of Velay, iv. 136.

-, on fossils of the carboniferous

strata, i. 203. 235. ; iv. '294.
Hiera, new island, ii. 162.
Highbeach, height of London clay at,

iv. 257.
Hilaire, M e Geof. St., on uninterrupted

succession in animal kingdom, ii. 362.
Hillswick Ness, action of sea on rocks

of, i. 398.

Himalaya mountains, animals inhabit-
ing the, i. 152.

, height of perpetual snow on, i.

194.
Hindoo cosmogony, i. 6.
Hindoo town, buried, iii. 199.
Hindostan, earthquakes in, ii. 58. 250
Hisinger, M., on greywacke rocks of

Sweden, iv. 299.
Hodgson, Mr., cited, i. 147.
Hoff, Von, on level of Caspian, i. 30.
, on Omar, i. 31.

— , on springs near Lake Urmia, i.

326.
., on encroachments of sea, ii. 10. 12.
, on gain of land in Red Sea, ii. 2S.
, on earthquakes, ii 54. 184. 249. :

420

INDEX

Hoff, Von, on buried city of Oojain, ii.200.
, on human remains in delta of

Ganges, iii. 245.

, , on a buried vessel, iii. 247.

Hoffmann, M., on new island in Medi-
terranean, ii. 147. ; ui. 393.

9 on elevation craters, ii. 152.

, on Sicily, iii. 390. ; iv. 39. 41.

., on agency of subterranean gases,

iv. 373.
Holbach, his theory, 1753, i. 58.
Holderness, marine strata of, iv. 76.

Holland, inroads of the sea in, ii. 5.

, submarine peat in, iii. 265.

Holm sand, near Lowestoff, i. 411.

Holstein, iv. 88.

Homer cited, i. 354.

Honduras, recent strata of, iv. 23.

Hooke, his " Discourse of Earthquakes,"

i. 47.

on distribution and duration of

species, i. 48, 49.

— on earthquakes, i. 51. ; ii. 258. 260.

on the deluge, i. 51.
Hooker, Dr., on eruption of Skaptar

Jokul, ii. 127.
, his view of the crater of the great

Geyser, ii. 343.
., on drifting of a fox on ice, iii. 105.

Hordwell, loss of land at, i. 426.
Hornblende schist, altered clay or shale,

iv. 376.
Horner, Mr., on sediment of Rhine, i.

366. ; iv. 35.
., on brine springs of Cheshire, i. 331.
., on limestone of Burdiehouse, iv.

294.

, on geology of Lower Rhine and

Eifel, iv. 38. 102. ill.
Hornitos on Jorullo, account of, ii. 135.
Horsburgh, Capt, on icebergs in low

latitudes, i. 177.

. , on coral islands, iii. 280. 291.

Horses, wild, drowned in rivers in South
America, iii. 234.

Horsfield, Dr., on earthquakes and erup-
tions in Java, ii. 209. 249.
., on distribution of Mydaus meliceps

in Java, iii. 39.

Horticulture, changes in plants pro-
duced by, ii. 399.

Hugi, M., on altered secondary strata
in the Alps, iv. 370.
., on modern granite in the Alps, iv.

344.

Human remains, changes in buried, m-

214.

in peat-mosses, iii. 183.

in caves, iii. 205. 207. 212.
— , their durability, i. 246. ; iii. 245.

— in delta of Ganges, iii. 245.

— in calcareous rock at Guadaloupe*

iii. 245.

in breccias in the Morea, iii. 205.

Humber, warp of the, i. 377. ; ii. 27.
, encroachment of sea in its estuary r

i. 403.
Humboldt on laws which regulate the

diffusion of heat, i. 166.

on preservation of animals in frozen

mud, i. 154.

— on distribution of land and sea, i.

194.

on transportation of sediment by

currents, ii. 33.
, his definition of volcanic action, ii-

40.

— on mud eruptions in the Andes, ii.

44.

on eruption of Jorullo, ii. 134.

on earthquakes, ii. 203. 208, 209.

on distribution of species, iii. 3. 5. 9,9-

on migrations of animals, iii. 48. 65.

112.

cited, i. 11. 147. 154. 174.
Humming-birds, distribution, &c, iii. 46.
Hungary, tertiary formations of, iv. 128^

, volcanic rocks of, iv. 140.

Hunstanton, its cliffs undermined, i»

404.
Hunter, John, on mule animals, ii. 423.
Hunter, Mr., on buried city of Oujein*

iii. 193.
Huron, Lake, recent strata of, iii. 262.
Hurricanes connected with earthquakes*

iii. 198.
, plants drifted to sea by, iii. 225.

Hurst Castle shingle bank, i. 425.
Hutchins on a landslip in Dorsetshire,.

i. 427.
Hutchinson, John, his " Moses's Prin-

cipia," 1724, i. 58.

, on Woodward's theory, i. 58.

Hutton, first to distinguish between
geology and cosmology, i. 5. 89.

on igneous rocks, i. 90.

on granite, i. 90.

represented oldest rocks as deri-
vatives, i. 92. ; iv. 391.
Hutton, Mr. W., on fossil plants of the

coal strata, i. 202. 231.

*w ^

INDEX

421

Hutton, Mr. W., on freshwater strata

of the coal period, iv. 294.
Huttonian theory, i. 89. 92. 95. 101.
Hybrid races, Lamarck on, ii. 372.

r animals, ii. 422.

plants, ii. 426.

Hydrogen, deoxidating power of, ii. 328.
-, why not found in a separate form

among volcanic gases, ii. 349.
Hydrophytes, distribution of, iii. 8. 16.
Hypogene, term proposed as a substitute

for primary, iv. 379.

formations, no order of succession

in, iv. 380.

rocks, their identity of character
in distant regions, iv. 381.

produced in all ages in equal quan-

tities, iv. 384.
■, their relative age, iv. 383.
., volume of, formed since Eocene

period, iv. 389.

Hythe, encroachments of sea at, i. 422.

Ianthinafragilis, its range, &c, iii. 56.
Ice, animals imbedded in, i. 156.

., drift, influence of, on temperature,
i. 169.

— , predominance of, in antarctic

circle, i. 175.

., formation of field, i. 191.

, transportation of rocks by means
of, i. 269.; ii. 289.; i v. 47, 48.

■, jointed structure of, iv. 360.
Icebergs, formation of, i. 156. 172.

, distance to which they float, i. 173.

177. 271.

., their influence on temperature,
i. 173.

•, plants and animals transported by,
iii. 16. 40.

rocks transported by, i. 270. ; ii.
289. ; iv. 47, 48.
Iceland, icebergs stranded on coast of,
i. 173.

, geysers of, i. 328. ; ii. 342.

■, volcanic region of, ii. 58.
— , volcanic eruptions in, ii. 126.
— , comparison between the lavas of
Central France and, ii. 129.
— , new island near, ii. 127. 145.

., polar bear drifted to, iii. 103.

Idienne, volcanic mountain of, iv. 178.
Igloolik, fossils of, i. 163.

Igneous action. See Volcanic.

Igneous causes. See Book ii.

, the antagonist power to action of

running water, i. 260.; ii. 354. ; iii.

161.

Iguanodon, fossil in Wealden and Kent-
ish rag, iv. 286.

Imbaburu volcano, fish ejected from, ii.
44.

Imbedding of organic remains. See Fos-
silization.

Imperati, theory of, 1590, i. 39.
India, Central, buried cities in, iii. 193.
Indus, recent changes in delta of, ii.
194. ; iii. 254. 265.

sections of the new-raised land

formed by, ii. 197. '
Indusial limestone of Auvergne, iv. 152.
Inkpen Hill, highest chalk in England,

iv. 259.

Inland cliff, near Dax, iv. 124.

on east side of Val di Noto, iii.
440.

Inland seas, deltas of, i. 344.

Insects, geographical distribution of, iii,

62.

, migrations of, iii. 63.

, certain types of, distinguish par-
ticular countries, iii. 64.

, their agency in preserving an

equilibrium of species, iii. 89.

, fossil, iii. 229.; iv. 210.

Instincts, migratory, occasional develop-
ment of, in animals, iii. 36.
, hereditary, ii. 409. 415.

, modified by domestication, ii. 413.

Insular climates, description of, i. 169.

Inverness-shire, inroads of sea on coast
of, i. 399.

Ionian Isles, earthquake in, ii. 194.

, new island near, ii. 194.

Ippolito, Count, on earthquake of 1783

in Calabria, ii. 212.
Ipsambul, buried temple of, iii, 189.
Irawadi, R., silicified wood of, noticed

in 1692, i. 49.

, recent discoveries of fossil animals
and vegetables, i. 49.

its supposed petrifying power, i.

329.

Ireland, raised beaches on east coast of,
i. 216.

., rise of sea, during Lisbon earth-
quake, on coast of, ii. 254.
— , reptiles of, iii. 50.
— , its flora little known, iii. 50.

^^F

422

INDEX,

Ireland, peat of, and fossils of peat in,

iii. 178. 183. 185.
, deposits in progress off coast of,

iii. 271.
., rocks altered by dil$es in, iv. 365.

Iron, melting point of, ii. 314.

in wood, peat, &c, iii. 182.

instruments, taken up from sea,

iii. 249.
Irtish, R., fossil bones on banks of, i.

148.
Irving, Mr. W., on migrations of the

bee, iii. 65.
Ischia, recent fossils of, i. 140. ; iv. 11.
- — , hot springs of, i. 329. ; ii. 188.
■, eruptions, and earthquakes in, ii.

62. 71. 188.
•, volcanic conglomerates forming on

shores of, iii. 396.
•, configuration of, how caused, iii.

297. ; iv. 13.
Islands, vegetation of small, i. 195. ;

iii. 6. 81.
, , animals in, i. 204. ; iii. 31.

in the Mississippi, i. 284.
— formed by the Ganges, i. 360, 361.
— , migrations of plants aided by, iii.

15.

— , new volcanic, i. 76. j ii. 127. 145,

146. 205.
», coral, iii. 274.
of drift-wood, iii. 41.
Isle of Bourbon, volcanic eruptions in,

iv. 350.
Isle of Cyclops, in bay of Trezza, iii.

401.
., contortions in strata of, iii. 403.

., lavas of, not currents from Etna,

iii. 405.
Isle of France, alternation of coral and

lava in, iii. 2y4.
Isle of Palma, description of, ii. 155.
Isle of Purbeck, line of vertical chalk

in, i. 425. ; iv. 260.
Isle of Wight, geology of the, iii. 335.
., fall of one of the Needles of, iv.

87.

9 freshwater strata of, iv. 215.

., mammiferous remains of, iv. 216.

263.
., vertical strata of, iv. 253. 259.
., action of the sea on its shores, i.

425.
Isonzo, R., delta of the, i. 350.

., its present mouth several miles
from its ancient bed, i. 352.

Isonzo, R., conglomerate formed by the,

i.352 .
Isothermal lines, Humboldt on, i. 166.
Isthmus of Sleswick, action of sea on,

ii. 8. ; iii. 129.
Italian geologists, their priority, i. 39.

of the 18th century, i. 59.

Italy, tertiary strata of, i. 59. 141. ; in-

335. 364.
, volcanic rocks of, iv. 89.

Jack, Dr., on island of Pulo Nias, iv. 23.
Jackson, Col., on jointed structure of

ice, iv. 360.
Jahde, new estuary of, ii. 8.
Jamaica, earthquakes in, ii. 46. 262. 278.
, subsidence in, ii. 262. ; iii. 125.

252. 255.
, rain diminished in, by felling of

forests, iii. 165.

— , a town swept away by sea in, iii-

199.
•, fossil shells of, iv. 23.

James, Mr., on bisons in Mississippi

Valley, iii. 35.
Jampang village engulphed, ii. 209.
Jan Mayen's island, volcanic, ii. 58.
Japan Isles, earthquake in, ii. 209.
Java, number of volcanos in, ii. 49.

, earthquakes in, ii. 209. 249. 259.

, subsidence of volcano of Papan-

dayang in, ii. 249. ; iii. 424.

vegetation destroyed by hot sul-

phuric water from a mountain in, iv

178.
, river-floods in, ii. 259- ; iii- 230-

Jesso, volcanos in island of, ii. 48.
Jobert, M., on extinct quadrupeds of

Mont Perrier, iv. 136.

., on hill of Gergovia, iv. 186.

, on Auvergne alluviums, iv. 197-

Johnston, Mr., on sinking of the waters

of Lake Maeler, ii. 294.
Jointed structure in rocks, iv. 358.
Jones, Sir W., on Menu's Institutes, i. 6-
Jorio, Andrea de, on Temple of Serapis,

ii. 274. 280.
Jorullo, eruption of, ii. 45. 133.

, its height, &c, ii. 133. ; iv. 350.

Juan Fernandez, ii. 185. ; iii. 115.
Jura, Saussure on the, i. 80.
, relative age of the, i. 211.

INDEX.

42*

Jura, erratic blocks of the, iv. 46.
Jutland, its northern part converted into
an island in 1825, ii. 9.
, inundations in, ii. 14.

Kamtschatka, active volcanos in, ii. 47.

, earthquakes in, ii. 259.

., new island near, ii. 205.
Kander, R., delta of, in lake of Thun,
iv. 68.

Kangaroo giving way in Australia, iii.
112.

Katavothrons of plain of Tripolitza
filled up with osseous breccias, iii. 205.

Kazwini on changes in position of land
and sea, i. 32.

Keferstein, M., on Fuchsel, i. 76.

Keill refutes Burnet's and Whiston's
theories, i. 58.

Keith on dispersion of plants, iii. 13.

Kent, loss of land on coast of, i. 415.

Kentucky, caves in limeston'e, iii. 202.

Kerguelen's land, quadrupeds in, i. 204.

Killas of Cornwall, iv. 368.

Kimmeridge clay, i. 427.

Kincardineshire, village in, washed
away by sea, i. 399.

King, Captain P., on currents in Straits
of Magellan, i. 385.
>, on coral reefs, iii. 280. 291.

King, Mr., on cattle lost in bogs in Ire-
land, iii. 185.

, on submerged cannon, iii. 249.

Kingsclere, valley of, iv. 246.

Kinnordy, Loch of, insects in marl in,

iii. 229.
., canoe in peat of, iii. 248.
Kirby, Rev. Mr., on insects, ii. 433.; iii.

63. 66. 93. 95.
Kir wan, his Geological Essays, i. £9.
on connection of geology and reli-
gion, i. 99.

on age of deltas, i. 342.
Knight, Mr., on varieties of fruit trees,

ii. 401.
Kolreuter on hybrid plants, ii. 426.
Kdnig, Mr., on rock in which the hu-
man skeletons from Guadaloupe are
imbedded, iii. 246.

., on fossils from Melville Island, i.
159.
Koran, cosmogony of the, i. 31*
Kossa cited, i. 32.

Kotzebue on drifted canoe, iii. 71.

■ on coral islands, iii. 279.

Krantz on migrations of seals, iii. 45.
Kupffer, M., on increase of heat in

mines, ii. 313.
Kured, upraised shelly deposits of, ii,

299.

Kurile Isles, active volcanos in, ii. 48.

Laach, lake-crater of, iv. 106.
Labrador, drift-timber of, iii. 224.
Laccadive Islands, iii. 280.
Lacepede on Egyptian mummies, ii. 397.
Lagoons, or salt lakes, in delta of Rhone,
i. 348. .
•, of coral islands, iii. 288.
Lagullas current, i. 169.
Lahn, valley of the, iv. 35.
Lake Aidat, how formed, iv. 200.
Lake Erie. See Erie, Lake.

of Geneva. See Geneva, Lake of.

Maeler, ii. 294. 301.

Mareotis, i. 354.

Superior. See Superior, Lake.
Lakes, bursting of, i. 292. 295.
, filling up of, i. 337. 34d.

formed by landslips in Calabria, ii.

233.

•, formation of, in basin of Missis-
sippi, i. 290.

formed by eartcquakes, ii. 203. 225.

233. 263.

, arrangement of deposits in, iii. 312.
L' Altar volcano, ii. 43.
Lamarck, his definition of species, ii.

363.

on transmutation of species, ii. 363.
398.; iii. 134. 139.

-[on conversion of the orang-outang
into the human species, ii. 377.
on abundance of polyps, iii. 149.
on fossils of Paris basin, iv. 50.
La Motta, in Sicily, iii. 400. 406.
Lamouroux on hydrophytes, iii. 8,
Lancashire, submarine forests on coasts
of, i. 431.

• , fossil canoes in, iii. 247.

, tertiary strata of, i. 215.; iv. 25.

Lancerote, volcanic eruptions in, ii. 139,
• 144.

Land, irregular distribution of, i. 193.
quantity of, in northern and
southern hemispheres, i. 176. 193.'

424

INDEX.

Land, proportion of sea and, i. 220.

., elevation of, how caused, ii. 339. ;

iii. 436.
Landers on delta of Niger, iv. 309.
Landes, tertiary strata of the, iv. 124.
Landguard Fort, waste of the point on

which it stands, i. 414.

Land-shells drifted to the sea by rivers,

iii. 360-5 iv. 33.
Landslips, i. 427. ; ii. 229. 231. 263.

., imbedding of organic remains by,

iii. 200.

., villages and their inhabitants bu-
ried by, iii. 200.

Langsdorf on new island, ii. 48. 205.

Languedoc, deposits on coast of, i. 349.

Lapidifying juice, i. 37.

Laplace on change in the earth's axis,

i. 57.
on mean depth of Atlantic and Pa-
cific Oceans, i. 185.

proved that no contraction of the

globe had taken place for 2000 years,

i. 222.

on mean density of the earth, ii. 312.

Lapland, why milder than Greenland,

i. 168.
., migrations of animals in, iii.'36, 37.
Lariviere, M., on drifting of rocks by

ice, i. 271.
La Roche, section of hill of, iv. 148.

Las Planas, lava current of, iv. 96.

Latham on range of birds, iii. 47.

Latitude influences climate, i. 176.

Latrielle on distribution of insects, iii.

63.
La Trinita, fossil shells of, iv. 66.

Latta, Dr., on glaciers of Spitzbergen,

i. 172.

Lauder, Sir T. D., on floods in Scotland,

i. 267. ; iii- 34. 197. 230. 233.
., on parallel roads of Glen Roy, iv.

18.
Laureana, ravines filled near, ii. 234.

Lava excavated by rivers, i. 272. ; iv.

93. 96. 193.
., effects of decomposition on, ii. 90.
., flowing of, under water, ii. 94.
., shells between two currents of, ii.

158. ; iii. 396.
., slope on which it congeals, ii. 173.

and coral alternating, iii. 294.

., minerals in cavities of, iii. 405.

., veins of. See Dikes.

., length of time which it requires

to cool, iv 350.

Lava, solid externally while in motion,

iii. 413.
and alluvium of different ages in

Auvergne, iv. 195.
of Iceland and Central France, ii.

129. 131.

comparative volume of ancient

and modern, ii. 132.

., pretended distinction between an-
cient and modern, ii. 142.
— , mineral composition of, ii. 175. 177.

351.
La Vissiere limestone, iv. 192.
Lawrence on causes which enable man

to live in all climates, ii. 438.
Lazzaro Moro. See Moro.
Leeward Islands, geology of the, iv. 22.
Le Grand d'Aussi, M., on Auvergne^

iv. 197.
Lehman, treatise of, 1759, i. 71.
Leibnitz, theory of, i. 46.
Leigh on fossil canoes, iii. 247.
Leith Hill, height of, iv. 230.
Lemings, migrations of, iii. 37.
Lena, R., fossil bones on banks of, f»

148, 149.
Lentini, limestone near, iii. 396.

, valleys near, their origin, iii. 442-

Lenz, M., on level of Caspian, iv. 203.
Leonhard, M., on loess of the Rhine, iv.

31.

38.

on volcanic district of Lower
Rhine, iv. 113.
., on granites of di fferen t ages, i v. 343.
Lepere, M., on level of Mediterranean

and Red Sea, i. 387.
Lesbos, Antissa joined to, by delta, i. 18.
Lewes, human bones in tumulus near,

iii. 214.
, estuary of the Ouse recently filled

up near, iii. 263.

Levels, iii. 229. 262.

fissures in chalk filled with sand

near, iv. 218.

— ,ravine called the Coomb near, iv.241.

, fault near, iv. 242.
Leybucht, bay of, ii. 8.
Lias, strata of the, iv. 290.

altered by trap dike and by granite,

iv. 367. 370. 384.
Licodia, basalts of, iii. 406.
Liege, caves near, iii. 211.
Light, influence of, on plants, i. 159.
Lightning, effect of, in Shetland Islands,.

i. 394.

Lignite, conversion of wood into, iii. 24&-

INDEX.

425

Lima destroyed by earthquake, ii. 258.

• , valley of, proofs of its successive

rise, iv. 17.

Limagne d'Auvergne. See Auvergne.
Limburg, loess near town of, iv. 32.
Limestone, origin of, iii. 299.

Lincolnshire, incursions of the sea on
coast of, i. 404.

Lindley, Mr. J., on fossil plants of Mel-
ville Island, i. 159.

., on effect of light on plants, i 159

~, on fossil plants of the coal strata,
1. 231. '

on number of plants, iii. 148.

— , on dispersion of cryptogamic plants
iii. 13. *

Linnaeus on filling up of Gulf of Both-
nia, ii. 288.

on constancy of species, ii. 353,
on real existence of genera, ii. 383.

- on diffusion of plants, iii. 18. 23.

- on introduction of species, iii. 77.
cited, iii. 89.

Lionnesse tradition in Cornwall i
430.

Lipari Islands, rocks altered by gases in

iv. 373. '

Lippi on destruction of Herculaneum

and Pompeii, ii. 97.
Lipsius, i. 21.
Lisbon, earthquakes at, ii. 57. 251. : iii.

252.

Lister the first to propose geological
maps, i. 4&

on fossil shells, i. 46.
Lloyd, Mr., on relative levels of Atlantic
and Pacific, i. 387.

Lloyd's List, number of wrecked vessels
as shown by, iii. 243.

Lpchead on gain of land on coast of
Guiana, ii. 33.

Loch Lomond, agitation of its waters
during Lisbon earthquake, ii. 253.

Lockart, M., on fossils of the Orleanais,
iv. 137.

Locke on Whiston's theory, i. 58.

Locusts, devastations by, iii. 95.

, bank formed in sea by, iii. 96.

Loess of the Rhine, iv. 29.

Loffredo cited, ii. 279, 280.

Loire, tertiary strata of the, iii. 338. :
iv. 115.

London basin, tertiary deposits of, i
214.J iii. 335.; iv. 211.

., on former continuity of Hampshire
and, iv. 219.

■•

London clay, its fossils, composition,
thickness, &c, i. 240. ; iv. 213.

Long, Mr., on earthquake at New Ma-
drid, ii. 204.

Long Point peninsula cut through by
Lake Erie, ii. 11.

Lough Neagh, supposed petrifying power
of, i. 329.

Louis de Foix, ii. 24.

Louisiana, Lower, marine strata of, i

292.

Lowe, Mr., on shells of Madeira, iii 58.
Lower green-sand described, iv. 222. 271 .
Lower Rhine. See Rhine.
Lowestoff, current off the coast of, i. 4] l,

Ness, description of, i. 411.

■ , cliffs undermined near, i. 411.

Lowland of Siberia, i. 153. 219.
Lubbock, Mr., i. 185.
Lubeck, ii. 288.

Lucina divaricata, wide geographical

range of, iii. 372. ; iv. 180.
Luckipour, its inhabitants swept away

by the Ganges, i. 363.

-, new islands formed near, i. 362.

Luckput, subsidence near, ii. 195.
Ludlow rocks, fossils of, i. 234.

, classification of, iv. 270. 298.

Ludwig, Baron, cited, iii. 15.
Luleo, gain of land at, i. 345. ; ii. 289.
Luy, tertiary strata of, iv. 120.
Luzon, active volcanos in, ii. 48.

Lybian sands, caravans overwhelmed
by, iii. 190.

Lyme Regis, waste of cliffs at, i. 429.

Lym- Fiord, a breach made by the sea
into, ii. 9.

Lyon, Capt.,on imbedding of camels in
African sands, iii. 190.

Maars, or lake-craters of the Eifel, iv.
104, 105.

MacCulloch, Dr., on gradation from
peat to coal, iii. 178.
•, on origin of limestone, iii. 299.

•, on parallel roads of Glen Roy, iv.
18.

-, on Subapennine strata, iv. 52.
-, on granite veins, iv. 338.
., on junction of granite and lime-
stone in Glen Tilt, iv. 340.

-, on granitic rocks, iv. 342, 343. 348.
371.

426

INDEX.

MacCulloch, Dr., on trap rocks, iv. 347.
Macedonia, earthquakes in, ii. 56.
Macgregor, Mr., on earthquakes in Ca-
nada, ii. 208. ,
Mackenzie, Sir G., his supposed section

of the pipe of a geyser, ii. 346.

9 on reindeer in Iceland, iii. 116.

Mackenzie, R., drift-wood of, i. 162. ; iii.

221.

., calcareous formation near its

mouth, i. 201.

Maclaren on quantity of useful soil in

America, iii. 117.
,on position of American forests, iii.

166.
Maclure, Mr., on coral and lava in

West Indies, iii. 294. ; iv. 22.

, on volcanic district of Olot, iv. 91.

Macmurdo, Captain, on earthquake of

Cutch, ii. 195. 199. ,

Madagascar said to contain active vol-
canos, ii. 58.

, extent of coral near, iii. 280.

Madeira, ii. 58. ; iv. 23.
Maeler, lake, ii. 294. 301.
Maestricht beds, fossils of, iv. 273.

, chasm between Eocene and, iv.

274.

., shells common to the chalk, green-
sand, and, iv. 272, 273.

Magellan, Straits of, currents in, i. 385.

Magnesia deposited by springs, i. 316.

Magnesian limestone and travertin com-
pared, i. 317-

Magnetism, terrestrial, phenomena of,

ii. 323.
Magnan, R., section in valley of, iv. 65.
Mahomet, his cosmogony, i. 32.

Majoli, opinions of, i. 38.
Malabar, coral near, iii. 280.
Malaga, tertiary strata of, iv. 70.
Malcolm, Sir J., on buried cities in Cen-
tral India, iii. 194.

Maldivas, chain of coral islands, iii. 280.

Mallet, Captain, on petroleum of Tri-
nidad, i. 334.

Malpais, theories to account for con-
vexity of the plain of, ii. 135.

Malte-Brun cited, i. 168. 181. ; iii. 42, 53.

71. 191. 224. 234.

Mammalia, different regions of indi-
genous, iii. 27.

, fossil, importance of remains of,

iii. 358.; iv. 40.

., of successive tertiary periods, iii.
379.

Mammalia, remains of, rare in the older

rocks, iv. 310.
Mammoth, climate, &c., probably re-
quired by the, i. 144.
., bones of, in Yorkshire, i. 145.
., in tufa near Rome, iv. 28.
Man, unfavourable position of, for ob-
serving changes now in progress, i.

121.

, recent origin of, i. 244. ; iii. I 1 ?*

255.
, remarks on the superiority of, *•

247.

— , causes which enable him to live in

all climates, ii. 438.
-, his agency in dispersion of plants

and animals, iii. 21. 74.
— , diffusion of, iii. 68.
— , probable birthplace of, iii. 68.
-, changes caused by, i. 252. ; iii- 106.

165.

— , durability of the bones of, i. 246. ;

iii. 245.
-, remains of, in osseous breccias of

the Morea, iii. 205.
., his remains and works fossil, iii-

234. 238.

Manetho, i. 113.

Manfredi on sediment in river water,

i. 366.

Mansfeld, fossils of, iv. 293.

Mantell, Mr., on bones from Saxon tu-
mulus, iii. 214.

, on Lewes Levels, iii. 229. 263.
— , on fossil shells of the crag, iv. 71-
— , on tertiary outliers on chalk, iv.

218.
., on the Weald Valley, iv. 222. 224.

235. 282.
_-, on " elephant bed " at Brighton,

iv. 261.

_., on fossils of the chalk, iv. 278.

— , on fossil forest of I. of Portland,

iv. 284.
-, on a fault in the cliff-hills near

Lewes, iv. 242.
Manwantaras, oriental cycle of ages, i. 7-

Maracaybo, lake, ii. 203.
Marble deposited from springs, i. 326.
Marculot, limestone of, iv. 152.
Marienforst, blocks of quartz, with casts

of shells near, iv. 112.

Marine alluviums, iii. 198.

Marine testacea, range of, iii. 361.

Marine and freshwater strata, alterna-
tions of, iii. 264.

•

INDEX.

427

Marine deposits, imbedding of fresh-
water species in, iii. 265.

, contain in general a great variety

of species, iii. 265.

Marine plants and animals, imbedding

of remains of, iii. 265.
Marine vegetation, iii. 8. 16.
Maritime Alps, conglomerates forming

at base of, i. 376.

., tertiary strata at base of, iv. 61.
Marl lakes of Scotland, animals and

plants fossilized in, iii. 236. 259.
Marsilli, on arrangement of shells in

Adriatic, i. 64. 67.

, on deposits of coast of Languedoc,

i. 349.

Marstrand, island of, ii. 297.

Marsupial animals, distribution of, iii.

29.

■, in breccias in Australian caves,

iv. 43.

Martigny destroyed by floods, i. 297.
Martin, Mr., on Valley of the Weald,
iv. 231. 281.

, on transverse valleys of North and
South Downs, iv. 238.

•, on thickness of strata removed from
summit of Forest ridge, iv. 258.
Martinique, earthquake in, ii. 259.
Martin Meer, fossil canoes in, iii. 247.
Martius, on drifting of animals by the
Amazon, iii. 42.

, on Brazil, iii. 108.

Maryland, whirlwind in, iii. 11.
Mascalucia, subsidence near, iii. 425.
Mathers, village of, swept away by sea,

i. 399.
Matilda coral island, iii. 290.
Mattani on fossils of Volterra, i. 60.
Mattioli on organic remains, i. 37.
Mayence, tertiary strata of, iv. 132.
Mayer, M., on mineral veins, iv. 375,
Mayne, Valjey of the, iv. 35.
Medesano, lignite at, iv. 54.
Mediterranean said to have burst
through the columns of Hercules, i.25.
■, microscopic testacea of, i. 78.
■, deposition of salt in the, ii. 15.
, its former union with the Red
Sea, ii. 31.
— , new island in, ii. 146.

., organic remains of, iii. 327. ; iv.
118.
— , shells drifted into, iii. 360.

., its temperature, depth, level, &c.
i. 79. 353. 387. ; ii. 14.16.272.

Medway, transverse valley of the, iv. 238,
Meerfelder Maar described, iv. 106.
Megalosaurus Bucklandi, iv. 286.
Melania inquinata, iii. 372.
Melilli, circular valley near, iii. 439.

■ , inland cliffs near, iii. 440.

Melville Island, fossils of, i. 159.

, migrations of animals into, iii. 41.

Mendip hills, caves of, iii. 212.
Menu's Institutes, i. 6. 8.
Mercati on organic remains, i. 37.
Merdogne, marls intersected by a dik
near, iv. 186.

Mersey, vessel in bed of, iii. 247.
Meryon, Mr., on Romney Marsh, i. 423.
Mese, formerly an island, i. 347.
Messenia, conglomerate of, iv. 277.
Messina, tide in Straits of, i. 381.

, earthquake at, ii. 218. 236.

Mesua Collis described by Pomponius

Mela, i. 347.
Metallic nucleus, theory of an unoxid-

ated, ii. 326.

Metallic substances changed by submer-
sion, iii. 249.

Metamorphic, the term proposed and
defined, iv. 380.

rocks of the Alps, iv. 369.

, sometimes pass into sedimentary,

iv. 382.

, in what manner their age should
be determined, iv. 383.

, why those visible to us are for the
most part ancient, iv. 384.
Methone, eruption in, ii. 56.
Metshuka, hill of, ii. 250.
Mexico, tides in Gulf of, i. 364.

, volcanic chain extending through,
ii. 45.

Meyen, Mr., on earthquake in Chili,
1822, ii. 191.

Meyer, Mr., on level of Caspian, iv.

203.

Mhysir, buried city, iii. 195.

Micaceous schist, whence derived, iv.

375.

Mich ell on cause and phenomena of
earthquakes, 1760, i. 73.
■, originality of his views, i. 73.
on the geology of Yorkshire, i. 73.
on earthquake at Lisbon, ii. 57-
254.

on retreat of the sea during earth-
quakes, ii. 255.

on cause of the wave-like motion

I of earthquakes, ii. 335.

428

INDEX.

I I

Microscopic fossil shells of Sienna, iv,

60.
., of the Crag, iv. 75.
of Paris basin, see plate, iv. 176.
Migrations of animals, iii. 36.
of cetacea, iii. 44.
of birds, iii. 45.
of fish, iii. I

- of insects, iii. 62.
Migratory powers indispensable to ani-
mals, iii. 120.

Mileto, subsidence near, ii. 252.
Milford Haven, rise of tides at, i. 382.

Miliolite limestone, iv. 176.

Millennium, i. 35. 55.

Mindinao volcano, ii. 48.

Mineral waters, their connection with

volcanic phenomena, i. 308.
., ingredients most common in, i.

311. See Springs.
Mines, heat in, augments with the

depth, ii. 313.
Miocene period, term whence derived,

iii. 370.
•9 proportion of living species in fossil

shells of the, iii. 370.
., mammiferous remains of, iii. 379.

, marine formations of, iv. 114.

•/freshwater formations of, iv. 137.

, volcanic rocks of, iv. 140.

. , alluviums of, iv. 134.

Mirambeau, red clay and sand of, iv.

122.
Mismer, crag strata near, iv. 79.
Mississippi, its course, depth, velocity,

&c, i. 281. 285.
., drift-wood of the, i. 284. 287. 365. ;

iii. 42. 223.
., earthquakes in valley of, i. 291. ;

ii. 46. 203.
., delta of, i. 364. 376.

Missouri, R., i. 282.
Misterbianco, valleys of, iii. 400.
Mitchell, Dr., on waste of cliffs, i. 415.

418.
Mitchell, Major, on Australian caves,

iv. 44.
Mitscherlich, M., on minerals found in

Somma, iv. 5.
Mocha, elevation of land at, ii 188.
Modern causes, remarks on the term,

iv. 264.
Moel Tryfane, recent marine shells on,

,i. 216.

Moen, chalk and tertiary strata of, iv-
87.

Molasse, its place in series of tertiary
formations not yet known, iv. 128.

Mole, R., transverse valley of, iv. 238.

Molino delle Caldane, travertin, i. 313.

Moluccas, eruption in the, ii. 261.

Molluscous animals, superior longevity

of the species of, i. 145. ; iii. 361. 372-5

iv. 40.
Mompiliere, articles preserved under

lava in, ii. 119.
Monfalcone, baths of, i. 352.
Mons, secondary strata near, iv. 271.
Mont Blanc, glaciers of, i, 269.

Dor, volcano of, ii. 170. 173. ; iv. 189-

Ferrat, tertiary strata of, iii. 338.

Mezen, age of the, iv. 188.

Perrier, alluviums and breccias of*

iv. 134.
Monte Barbaro, description of, ii. 75.
Bolca, fossil fish of, i. 78.

— Calvo, section from, to the sea, iv*

67.

Cerio, shells in gypsum of, iv. 54.

Grifone, caves in, iv. 41.

Mario, strata of, iv. 29. 56.

Minardo, its height, &c, ii. 113.

— Nucilla, ii. 113.

— Nuovo, formation of, ii. 72. ; hi

435.; iv. 11.14.

coast of Bay of Baise elevated dur-
ing eruption of, i. 51. ; ii. 72. 280.

Peluso, ii. 114.

Rotaro, ii. 63.

Somma, structure of, ii. 86. 168.

Vico, siliceous incrustations of, *■

329.

Monticelli and Covelli on Vesuvian mi-
nerals, ii. 92.

Monti Rossi described, ii. 116.

Montlosier on Auvergne, i. 87. ; iv. 192.

197.
Montmartre, gypsum of, iv. 172.

— , fossils of, iv. 179.

Montpellier, cannon in crystalline rock

at, i. 349.

, tertiary strata of, iv. 126.

Montsacopa, volcanic cone of, iv. 93.
Morayshire, town in, destroyed by sea, i-

399.

, effect of floods in, iii. 197. 233.

Morea, cities submerged in the, ii. 55.
Ceramique of, iii. 200.
, osseous breccias now forming ' n

the, iii. 203.

— , closed basins and engulphed rivers

| in the, iii, 204.

INDEX

429

■

Morea, human remains imbedded in the,

iii. 205.
, sea-cliffs at various elevations in

the, iv. 19.
, tertiary strata of, iv. 70.
., cretaceous rocks of the, iv. 277.
Morren, M., on peat, iii. 187.
Moro, Lazzaro, on earthquakes, 1740, i.

60.
, on new island in Mediterranean, i.

61.

, on nature of organic remains, i. 61.

, on faults and dislocations, L 61.

, on secondary strata, i. 62.

., on origin of stratified rocks, i. 67.
., on primary rocks, i. 91.
Morocco, earthquakes at, ii. 57. 253.
Moropano, shells in tuff near, iv. 12.
Mosasaurus of Maestricht found in the

English chalk, iv. 278.
Mosenberg, extinct volcano, iv. 106.
Mountain chains, on the elevation of, i-

116.
, on relative antiquity of, iv. 320.

, difficulty of determining the rela-
tive ages of, iv. 334.

Mountain limestone formation, i. 201. ;
iv. 293.

Mount Vultur, ii. 57.

Mud eruption in Quito, 1797, ii. 206.
Mules sometimes prolific, ii. 424.
Mundane egg of Egyptian cosmogony,

i. 16.
Mundesley, chalk near, iv. 85.
Munkholm, Island of, ii. 302.
Munster, Count, on Maestricht fossils,

iv. 274.
., on fossils of Solenhofen, iv. 289.

9 on Gosau fossils, iv. 279.

Murat, deposits near, iv. 192.

Murchison, Mr., on the Hartz moun-
tains, i. 184.
— , on tertiary deposits of the Alps, i.

210.

— , on the coal strata, i. 202. ; iv. 295.

— , on transition fossils, i. £34.

— , on schists of Caithness, i. 235.

— , on tertiary strata of Lancashire, i.

215.

on raised beaches in Ireland, i.

216.

on tertiary strata of Nice, iv. 25.
of maritime Alps, iv. 64. 65.
of the Superga, iv. 127.
ofStyria, iv. 129. 131. 142.
of Cadibona, iv. 140.

Murchison, Mr., on tertiary strata of
Central France, iv. 144. 162. 185. 192.

of Aix, iv. 211.
— , his section of crag resting on chalk,
iv. 77.
•, on excavation of valleys, iv. 195.
, on upper green-sand, iv. 248.
: , his new arrangement of the tran-
sition strata, iv. 298.
Murcia, earthquake of 1829, ii. 183.
Murphy, Lieut. H., on height of North

Downs, iv. 224.
Musara, buried cones near, iii. 415.

, flowing of lava round, iii. 420.

Muschelkalk, iv. 292.

Mydaus meliceps, iii. 39.

** T*

Nadder, valley of the, iv. 250.
Nakel, fossil ship found at, iii. 247.
Nantucket, banks of, i. 384.
Naples, history and map of volcanic
district round, ii. 61. $ iv. 1.

, recent tertiary strata in district

round, iii. 340.

■, recent shells in tuffs near, iv. 11.

Narwal stranded near Boston, iii. 266.

fossil, near Lewes, iii. 263.

Nature, as defined by Lamarck, ii. 375.

Necker, M. L. A., on Somma, ii. 168.
iv. 5. 8.

Needles of Isle of Wight, i. 425.

, fall of one of them, iv. 87.

Neill on whales stranded, iii. 266.

Nelson, Lieut., on coral reefs, iii. 279.

Neptune, temple of, under water, ii. 276.

Neptunists and Vulcanists, rival factions

of, i. 88. 98.

Nerbuddah, R., iii. 194.

Nerinaean limestone, iv. 289.

Nesti, M., on fossils of Upper Val d'Arno,

iv. 139.

Netherlands, tertiary formations of the,

iv. 210.

Newcastle coal-field, i. 202.

Newer Pliocene period. See Pliocene

period, newer.
Newfoundland, cattle mired in bogs of,

iii. 185.
Newhaven, its cliffs undermined, i. 423.

. tertiary strata on chalk near, iv.

222.
New Holland, plants of, i. 196. ; iii. 5.

430

INDEX.

New Holland, animals of, ill- 29.

, coral reefs of, iii. 280.

New Kameni, formation of, ii. 163.

New Madrid, earthquakes at, ii. 203.

New York, excessive climate of, i. 169.

New Zealand, animals in, i. 204.

Niagara, excavation caused by the cata-
ract of, i. 134. 277.
-, falls of, i. 275.

., probable time which they will re-
quire to reach Lake Erie, i. 278.

Niapisca Island, worn limestone co-
lumns in, iv. 21.

Nicaragua, volcanos in, ii. 45.

Nice, depth of Mediterranean near, i.

353. 376. ; ii. 18.
— , tertiary strata of, i. 353. ; iv. 63. 65.
Nicolosi destroyed by earthquake, ii.116.
Niebuhr cited, i. 109.
Niger, delta of, its size, iv. 309.
Nile, delta of the, i. 353. ; iii. 348.
., its ancient mouths, i. 354.
•, analysis of mud of the, i. 355.
, cities buried under blown sand
near the, iii. 188.
, men swept away by flood of, iii.

239.

Niisson, M., on lignite of the chalk pe-
riod, iv. 278.

on migrations of eels, iii. 54.

Nipon, volcanos numerous in, ii. 48.
Nitrogen in springs, iii. 158.
Noeggerath, M., on volcanic district of

the Rhine, iv. 102. 113.
Norfolk, waste of cliffs of, i. 404. ; iv.

23d.

, gain of land on coast of, i. 407.

, crag strata of, iv. 71.

Norte, R., transportation of sediment

by the, ii. 33.
North Cape, drift-wood on, iii. 224.
North Downs, chalk ridge called the, iv.

223.
. , section across valley of Weald

from south to, iv. 224.

, highest point of, iv. 224.

■ , on former continuity of chalk of

the, with that of the South Downs,

iv. 244.
Northmavine, rocks drifted by sea at, i.

394.
Northstrand destroyed by sea, ii. 9.

Northumberland, land destroyed by sea

in, i. 402.
Noto, Val di, formations of the, iii. 383.
Notre Dame des Ports, i. 347.

Norway free from earthquakes, ii. 304.

, rise of land in,i. 216. ; ii. 298. 301-

Norwich once situated on an arm of the

^ ■

sea, i. 407.
Nugent, Dr., on Pitch Lake of Trinidad,

i. 334.
Novera, hill of, in Sicily, iii. 392.
Nymphs, temple of, under water, n

276.
Nyoe, a new island formed in 1783, ii*

127. 145.

Obsequens on eruption in Ischia, ii. 71*
Oby, R., fossils on shores of, i. 148.
Ocean, permanency of its level, ii. 284.
Oceanic deltas, i. 357.
Odoardi on tertiary strata of Italy, i.

74. ; iii. 336.
Oersted, discoveries of, ii. 324.

Ogygian deluge, ii. 52. 69.
Ohio, junction of, with Mississippi, i. 282.
Olafsen on drift-wood, iii. 225.
Older Pliocene period. See Pliocene pe-
riod, older.
Old red sandstone formation, iv. 295.

, fossils of, i. 235. ; iv. 296.

Olivet, volcanic cone of, iv. 93.
Olivi on fossil remains, i. 38.

on sediment in Adriatic, i. 352.

Olot, volcanic district of (see PL xi.), iv.

90.

, destroyed by earthquake, iv. 99.

Omalius d'Halloy on former connection

of Auvergne and Paris basin, iv. 165.
Omar, an Arabian writer, i. 30.
Oojain. See Oujein.
Oolite, or Jura limestone formation, iv.

287.
, converted into hypogene rock in

the Alps, iv. 370.

, fossils of the, i. 237. ; iv. 288.

Oolitic structure in Auvergne, iv. 152.

in Hungary, iv. 130.

, recent, in Lancerote, ii. 144.

Opossum, fossil, at Stonesfield, i. 237-
Oppido, changes caused by earthquake

near, ii. 215. 224.

Orang-outang, Lamarck on its conver-
sion into the human species, ii. 377-

Organic life, effect of changes in land
and sea on, i. 182.

Organic remains, controversy as to real

nature of, i. 34. ; iii. 306.

)

INDEX.

431

Organic remains, imbedding of. See
Fossilization.

., importance of the study of, i. 106.

•, abrupt transition from those of
the secondary to those of the tertiary
rocks, i. 212.

contemporaneous origin of rocks
proved by, iii. 325.

, comparative value of different
classes of, iii. 357.

See also Fossils.
Orinoco, R., subsidence in, ii. 250.
Orkney Islands, promontory cut off by
sea in, i. 399.

Orleanais, fossils of the, iv. 137.

Orpheus cited, i. 13.

Orthes, tertiary strata of, iv. 121.

Orust, island of, ii. 300, 301.

Orwell river, i. 415.

Osnabruch, tertiary strata of, iv. 133.

Osseous breccias, formation of, iii. 231.

, in caves, iv. 38. 43.

, now forming in the Morea, iii. 203.

Otaheite, volcanos in, iii. 288.

, coral at great height in, iii. 297.

Otranto, tertiary strata of, i. 141.; iii.

340.
Oujein, buried city of, ii. 200. ; iii. 193.
Ouse, Ii., transverse valley of, iv. 238.

., has filled up an arm of the sea, iii.
263. ; iv. 240.

Outlying patches of tertiary strata on

chalk hills, iv. 218.
Ovid cited, i. 16.

Owen, Mr., on bones of turtles, iii. 269.
Owhyhee, iii. 288.

Owthorne, encroachment of sea at, i. 403.
Oxus, earthquake in valley of the, ii. 50.
Oxygen, its action on rocks, i. 262.
Oysters, &c, thrown ashore alive by
storm, iii. 270.

•, migrations of, iii. 60.

Pachydermata abundant in Eocene pe-
riod, iii. 379.

Pacific Ocean, depth of, i. 185

., its height above the Atlantic, i. 387.
— , animals in islands of, iii. 32.
— , subsidence greater than elevation
in, iii. 294.
— , earthquakes in, iii. 296.

, coral and volcanic islands of, ii.
49.; iii. 284. 287. 296.

Pacific Ocean, lines of ancient sea cliffs
on shores of, iv. 17.

Pssturn, formation of limestone near i
319.

Pakefield, waste of cliffs at, i. 411.
Palajotherium in freshwater strata of

Isle of Wight, iv. 216. 263.
Palagonia, dikes at, iii. 391.
, section to Paterno from, iii. 399.

Palermo, caves containing osseous brec-
cias near, iv. 41.

Palestine shaken by earthquakes, ii. 54.
Palissy on organic remains, i. 39.
Pallas on mountains of Siberia, i. 79.
on Caspian Sea, i. 80. ; ii. 52.

on fossil bones of Siberia, i. 80. 148
149.

— on calcareous springs, i. 325.
cited, ii. 12. 53. 320. ; iii. 75.

Palma, description of Isle of, ii. 155.
Palmer, Mr., on shingle beaches, i. 428.
Panama, tides in Bay of, i. 388.
Panella, in Ischia, iv. 13.
Papandayang, eruption of, ii. 249.

, its cone truncated, ii. 249 - iii

424. ' '

Papa Stour, waste of rocks of, i. 398.

Papyrus rolls in Herculaneum, ii. 104.

Paradise, Burnet on seat of, i. 56.

Parallel roads of Coquimbo, iv. 18.

of Glen Roy, iv. 18.

Paris basin, formations of the, i. 214 -
iii. 332. ; iv. 164.

, fossils of the, i. 240. ; iii. 333. 372 :

iv. 176, 177.

, all tertiary formations at first re-
ferred to age of, iii. 334.

, analogy of deposits of Central

France to those of the, iv. 164.

, comparison between English Eo-
cene deposits and those of, iv. 217.

Parkinson, Mr., on the crag, iii. 335 •
iv. 50.

Parma, tertiary strata near, i. 141. 353, •
iii. 364. ; iv. 53.

Paroxysmal elevations, theory of, iv. 14.

Parrot on Caspian Sea, ii. 51. ; iii. 126.

, retraction of his opinion on level

of Caspian, iv. 202.

Parry, Captain, highest northern lati-
tude reached by, i. 175.

on migration of Polar bear, iii. 40.
on animals of Melville Island, iii.
41.
Partsch, M., on tertiary strata of Vi-
enna, iv. 129. "

422

INDEX

Passo Manzanelli, waterfalls in lava at,

i. 274.
Pasto, volcanos in, ii. 45.
Paterno, section from, to Palagonia, iii.

399.

, valleys of, iii. 400.

9 age of basalts of, iii. 406.

Patrizio's dialogues, i. 59.

Pauliac, limestone of, iv. 122.

Paviland cave, iii. 212.

Peat, on its growth and preservation of

fossils in it, iii. 160. 177. 182.
bogs, bursting of, iii. 186.
., submarine, iii. 187. 265.
Padamentina, description of the, ii. 87.
Pembrokeshire, tradition of loss of land

in, i. 431.
Pennant on encroachments of sea on

Yorkshire coast, i. 403, 404.

on distribution and migration of

animals, i. 147. ; iii. 31. 37.
Pentalica, limestone of, iii. 384, 385.
Pentland, Mr., on fossils from Australian

caves, iv. 44.
., on fossils of Upper Val d' Arno, iv.

138.
Pentland Frith, currents in the, i. 385.

Penzance, loss of land near, i. 429.

Peperino, dikes in, iii. 390.

., how formed, iii. 393.

., dikes of, how formed, iii. 392.
P£ron on distribution of animals, iii. 52.

61.
Perpignan, iv. 99.

Persian Gulf, coral in, iii. 280.

Persian Magi on the deluge, i. 32.

Peru, volcano in, ii. 42.

•, earthquakes in, ii. 42. 258.

, proofs of successive elevation of

coast of, iv. 17.
Peterhead, whale stranded near, iii. 266.
Petroleumi springs, i. 334.
Pewsey, Vale of, iv. 250. i

Pharos joined to Egypt by delta of Nile,

i. 18. 354.
Phillips, Mr. J., on waste of Yorkshire

coast, i. 403.
9 on tertiary strata in Yorkshire, iv.

Phillips, Mr. R., on slow deposition of

some kinds of sediment, ii. 35.
Phillips, Mr. W., his analysis of chalk

flints, iv. 160.
Philosopher's tower on Etna, iv. 15.

Phlegraaan fields, volcanos of, ii. 74. ;
iv. 10.

Physical Geography. See Geography,
Piana, conglomerate of, iv. 127.
Piazza, tertiary strata at, iii. 326.
Pichinca volcano, ii. 43.
Piedmont, tertiary strata of, iii. 338. ; iv.

126.
Pietra Mala, inflammable gas of, i. 19.
Pignataro on earthquake of Calabria, ii«

212.
Pigs, instincts of, ii. 413. '

swim to great distances, iii. 34.

, fossil, iii. 183.

Pindar cited, ii. 115.

Pingel, Dr., on subsidence of Greenland,

ii. 342.
Pitch lake of Trinidad, i. 334.
Pitchstone, formed by dikes of Somma,

iv. 9.
Piteo, gain of land at, i. 345. ; ii. 289.
Pius VII., edict against Galileo and Co-

■

pernican system repealed by, i. 100.

Piz, fall ofmountain of, iii. 200.
Plants, varieties in, produced by horti-
culture, ii. 399.

, extent of variation in, ii. 401.

their geographical distribution,

in. 3.

in islands, iii. 6. 15.
, dispersion of, iii. 10.
., stations of, iii. 5. 86.
-, equilibrium among, kept up by in-

sects, iii. 89.

— , number of terrestrial, iii. 148.

•, imbedding of, in subaqueous de-
posits, iii. 219. 258. 265.

., on number which are now becom-
ing fossil, iii. 226.

►, their fossilization partial, iii. 350.

., fossil, importance of, in geology t

iii. 357. 359.
., fossil, of the coal strata, i. 158. 202.

231.
Plas Newydd, changes caused by a dike

near, iv. 364.

Plastic clay and sand of the London ba-
sin, i

of the Paris basin, iv. 168.

Plastic force, fossil shells ascribed to, i.

34.
Plato on Egyptian cosmogony, i 13.

Play fair on Huttonian theory, i. 94. 101.

on instability of the earth's surface,

i. 299.

. on gradual rise of Sweden, ii. 291.

on formation of vegetable soil, iii*

240. : iv. 212.

156,

INDEX,

433

Playfair cited, ii. 320.

Pleurs town of, and its inhabitants bu.

ned by a landslip, iii. 201 .
Pliny the Eider, i. 27.

■, on delta of Rhone, i. 346

-, on islands at the mouth of the
Texel, 11. 7.

.killed by eruption of Vesuvius,
a. d. /9, 11. 67.

Pliny the Younger, on eruption of Ve-
suvius, a. d. 79, ii. 67

— , does not mention the overwhelm,
ing of Herculaneum and Pompeii, ii.

U/ »

Pliocene period, newer, derivation of
the term, iii. 368.

, proportion of living species in fos-
sil shells of, iii. 369. 373.
■— , marine formations of, iii. 382.

, volcanic rocks of, iv. 2.

— -, subterranean rocks of fusion
formed during, iii. 436. '

-, freshwater formations of, iv. 27.

-, osseous breccias and cave deposits
of, iv. 38.

, alluviums of, iv. 44.

Pliocene period, older, proportion of
living species in fossil shells of, iii
369. 373. *

', mammiferous remains of, iii. 379
■, formations referable to the, iv. 49.'
-, volcanic rocks of, iv. 89
Pliocene strata of Sicily, origin of, iii.

'iOOm

•, changes of surface during and
since their emergence, iii. 438.
— •, newer, chiefly visible in countries
of earthquakes, iv. 16.26.

Plomb du Cantal, successively accumu-
lated, iv. 162.

•, volcanic rocks of, iv. 188. 191.

•, limestone covered by volcanic
rocks on, iv. I92.

, not an elevation crater, ii. 170.

Plot on organic remains, i. 45.
Pluche, theory of, 1732, i. 58.
Plutarch, i. 12.
Plutonic rocks, iv. 337.

•, distinction between volcanic and,
iv. 345.

>, their relative age, iv. 351. 383.

■, changes produced by, iv. 368.
Po, R., frequently shifts its course, i. 279.
■, embankment of the, i. 280.

' delta of th e, i. 350. 374. ; iii. 170.
Podoha, tertiary formations of, iv. 132.

VOL. IV. U

Polistena, changes caused by earth-
quakes near, ii. 219. 226. 231.
Polyps, see Zoophytes.
Pomerania, fossil ships in, iii. 247.
Pompeii, how destroyed, ii. 94. 98.

■ » section of the mass enveloping.

ii. 95.

, depth to which the ashes of erup

tion of 1829 covered, ii. 25.

, objects preserved in, ii. 100.

Pomponius Mela, cited, i. 347. ; ii. 6.
Pondres, cave at, iii. 214.
Pontanus on eruption in Ischia, ii. 71-
Pont du Chateau, tuff and limestone at,

iv. 185.

Ponte Leucano, travertin at, i. 321.
Pont Gibaud, gneiss rocks decomposed
by carbonic acid at, i. 332.

, calcareous springs near, i. 812.

Poole Bay cut into by sea, i. 426.

Popayan, volcanos in, ii. 45.

-, shaken by earthquake, ii. 189.

Port-au-Prince destroyed by earthquake,
ii. 255.

Portland, fossil ammonites of, i. 49.

, its peninsula wasting, i. 427.

, fossil forests in, iv. 284.
Port Royal, subsidence of, ii. 262. : iii
125. 252. 255.

Portugal, earthquakes in, ii. 57. 251.

Port Vallais, ancient town in delta of

Rhone, i. 338.
Po Vecchio, i. 280.
Pratt, Mr., on fossils of Isle of Wi»hf

i. 241. ; iv. 216. * '

, on cave of San Ciro, iv. 40.

Precession of the equinoxes, i 179
Prevost, M. C, on fossil mammalia

of Stonesfield, i. 237.

■>on gypseous springs of Baden, i.

-, on new island in Mediterranean
11. 148. '

•, on elevation craters, ii. 152. 154.

, on geological causes, iii. 176.
•, on drifting of plants, iii. 223.
, on filling up of caves with osseous
breccias, iii. 210.

on tertiary strata of Vienna iii

339. ; iv. 128. '

— , on tertiary strata of Paris basin

iv. 167. 171. 173. 178.
Prevost, M. P., on radiation of heat, i. 167
Prevost, Mr. J. L., on number of wrecked

vessels, iii. 243.

434

INDEX.

Pressure, effects of, on consolidation of

strata, iv. 317.
Prichard, Dr., on Egyptian cosmogony,

i 12. 250.
' , on recent origin of man, i. 246.

.' on distinct origin of dog and wolf,

on hybrid races, n. 42o.
\ on facial angle, ii. 437.
. on distribution of animals, iii. 28.

31.' ,

Primary, on the rocks usually termed,

iii. 313. ; iv. 336.

., their relation to volcanic and sedi-
mentary formations, iv. 336.

., divisible into two groups, iv. 337.

., on the stratified rocks called, in.

317. ; iv. 353.
. the term why faulty, iv. 379.
'strata, how far entitled to the ap-
pellation, i v. 383.
Primitive, term now abandoned, m. <518.
Primosole, limestone at, iii. 397.
Prinsep, Mr., on sediment of Ganges, i.

367.
Priory of Crail, swept away by sea,

i. 401. , ■ . .

Procida, island of, remarks of ancient

, writers on, ii. 62.
would resemble Ischia if raised,

Progressive development of organic life,

theory of, i. 227. ; ii. 363.
Promontories, their effect in protecting

low shores, i. 399.
Psalmodi, formerly an island, i. 347.
Puglia, fossil elephant found at, i. 37.
Pulo Nias, fossil shells of, iv. 23.
Pulvermaar, described, iv. 105.
Punto del Nasone, dikes at, iv. 6.
Punto di Guimento, veins of lava at,

iii. 419.
Purace volcano, iv. 178.
Purbeck, its peninsula wasting, i. 427.
Pursh on Plants of United States, iii. 5.
Pusanibio, R., sulphuric acid, &c. in

waters of, iv. 178. .

Puy Arzet, chalk with beds of tuff in,

iv. 120. .

Puv de Come, ravine in lava of, iv; 193.

Puy de Jussat, quartzose grits of, iv. 148.

Puy de Marmont, tuff and marl in, iv.

185.
Puy de Pariou, iv. 199.

Puy Griou,iv. 191. . x

Puy Rouge, ravine in lava of, iv. i94.

Puy de Tartaret, iv. 193.

Puy en Velay, fossils in alluvium under

lava near, iv. 136.
. freshwater formation of, iv. 15/.

' __ it OC

- neon v* utv* aw**-- — * — — z r\r**~

Puzzuoli, Temple of Serapis near, ii. 26/ .
s inland cliffs near, ii. 268. 2/0. ;

iii. 441. ..
, date of re-elevation of coast of, n.

., encroachment of sea near, u. AZ.
' no great wave caused by rise of

coast near, iv. 14.
Pyrenees, their relative age, height, &c,

i. 211. ; iv 326. 368.
9 tertiary formations of, iv. 69. so.

327.
./lamination of clay-state in, iv. 361-

.' chalk of the, iv. 276, 277.
Pythagoras, system of, i. 16.
., on Etna, ii. 39.

Quadrumanous animals, not found fos-
sil, i. 242. %A ,
Quadrupeds, domestic, multiply rapidly

in America, iii. 113.
} imbedding of terrestrial, iii. 231.

Quaggas, migrations of, iii. 38.
Ouartz, whence derived, iv. 376.
Quebec, climate of, i. 169.

, earthquakes in, ii. 208.

Quero destroyed by earthquake, ii. 207.
Quilotoa, Lake, cattle killed by vapours

from, ii. 207.
Quintero elevated by earthquake or

1822, ii. 190.
Quirini, theory of, i. 44.
Quito, earthquakes in, ii. 206. 261.
Quorra, or Niger, delta of the, iv. 309.
Quoy, M., on coral zoophytes, iii. 281.

Raben stein cave, iii. 210.

Race of Alderney, its velocity, k o*o-

Radicofani, marls capped by basalt at,

iv 54*.
; ., age of volcanic rocks of, iv. 89-

Rad'usa, fossil fish of, iii. 389.

Raffles, Sir S., cited, ii. 200. 419.

Rafts, drift-timber in Mississippi, & c -»

i. 286.
Rain, action of, iii. 164.

INDEX.

435

Rain diminished by felling of forests,
iii. 165.

Ramazzini on Burnet's theory, i. 59.
Ramond, M.\ on Auvergne, iv. 197.
Rancid, altered lias at, iv. 369.
Raspe on islands shifting their position
(note), i. 19.

"., his theory, 1763, i. 75.
, on earthquakes, i. 75.
-, on new islands, i. 76.
■, on basalt, i. 85.

■, on elevation of coast of Chili, ii.
258.
Rats, migrations of, iii. 37.

introduced by man into America,
iii. 74. 115.
Ravenna, formerly a sea-port, i. 351.
Ray, his physico-theology, i. 52. 54.

, on earthquakes, i. 53.

•—. — , on encroachments of sea, i. 53. 413.

, on Woodward's theory, i. 55.

, cited, iii. 50.

JEteaumur on insects, iii. 94.
Recent formations, term explained, iii.

ooo.

, form a common point cf departure

in all countries, iii. 378.

Recent and tertiary formations, synop-
tical table of, iii. 381.

Reculver cliff, encroachment of sea on,
i. 416.

Recupero on flowing of lava, ii. 119.

Red marl, supposed universality of, iv.
315.

and sandstone of Auvergne, iv.

148. 316.

Red River, formation of new lakes by,
i. 290. ; iv. 37.

, drift-wood in, i. 286.

Red River and Mississippi, their junc-
tion recent, i. 374.

Red Sea, gain of land in, ii. 28.

, level of, i. 387.

, coral reefs of, iii. 275. 282. 288. 292.

, on former union of Mediterranean

and, ii. 31.

and Mediterranean, distinct spe-
cies in, iii. 328. ; iv. 118.
., tertiary strata on borders of, iv. 25.

Refrigeration, Leibnitz's theory of, i.
46.

. ., causes which might produce the

extreme of, i. 186.
Rein-deer, geographical range of, iii. 36.
., migrations of, iii. 41.
, imported into Iceland, iii. 116.

Rennell, Major, on delta of Ganges, i.
358. 362.
•, on icebergs, i. 173.
-, on delta of Nile, i. 353.

-, on sediment in waters of Ganges,
i. 367.

•, on currents, i. 170. 382. 384. 386.

-, on the tide- wave called the Bore,
ii. 10.

Rennes, tertiary strata near, iv. 209.

Rennie, Rev. Dr., on peat, and fossils in

peat, iii. 1/7, 178. 182. 188.

Reptiles, their geographical distribution,
iii. 49.

, their powers of diffusion, iii. 50.

, in Ireland, iii. 50.

, imbedding of, in subaqueous depo-
sits, iii. 230. 234. 267.
Resina, overflowed by lava, ii. 77.
Rhine, R., description of its course, ii.

, its delta, ii. 2.

, Lower, volcanos of the, iv. 101.

, origin of trass of, iv. 108.

Rhinoceros, fossil, in Siberia, i. 150.

Rhone, delta of, in Mediterranean, i
345.

, delta of, in Lake of Geneva, i. 337.

372.'; iii. 346.
•, debris deposited at its confluence

with the Arve, i. 378.
— , shells drifted by the, iii. 360.
, a cannon imbedded in calcareous

rock in its delta, iii. 249.
Riccioli, Signor, on travertin, iv. 28.
Richardson, Dr., on formation of ice-
bergs, i. 156.
, on a calcareous formation near the

Mackenzie River, i. 201.
•, on drift- timber in the Mackenzie

and Slave Lake, iii. 221. 223.
Richardson, Mr. W., on Heme Bay, ii.

416.
Riobamba destroyed by earthquake, ii.

207.
Rimao, valley of, ancient sea-cliffs in

iv. 17.
Ripple marks, how formed, iv. 81.
Risso, M., on fossil shells, iv. 25. 66.
Rita, hot spring of, its temperature

raised by earthquake, ii. 188.
Rive, M. de la, on terrestrial magnetism

ii. 324.
Rivers, difference in the sediment of

i. 135. 345. 349. 373. ; iii. 326.
., sinuosities of, i. 263.

436

INDEX,

Rivers, two equal, when they become
confluent, do riot occupy bed of dou-
ble surface, i. 265.

Robert, M., on fossils of Cussac, iv. 137.

Rocco di Ferro, shells in tuffs of, iii.

402. "
Rochester, indentations in the chalk

filled with sand, &c. near, iv. 217.
Rockall bank, recent deposits on, iii.

271.
Rocks, specific gravity of, i. 264.

, altered by subterranean gases, i.

iv. 373.

-, distinction between sedimentary

and volcanic, iii. 313. ; iv. 337.

», origin of the primary, iii. 314. ; iv.

350.

., distinction between primary, se-
condary, and tertiary, iii. 313.
— persistency, of mineral character,
why apparently greatest in the older,

iv. 313.
., older, why most consolidated and

disturbed, iv. 316. 318.

., secondary volcanic, of many dif-
ferent ages, iv. 319.

., relative age of, how determined,

iii. 319.
., transportation of, by ice, i. 269. ;

ii. 289. ; iv. 48.

cleavage planes and jointed struc-

ture of, iv. 354.

—, how altered by permeation of heat

and gases, iv. 372.
, chemical composition of different,

iv. 377.

Roderberg, crater of the, iv. 34. 106.
Rogvarpen, Lake, strata near, ii. 301.
Roman roads under water in Bay of

Baia?, ii. 276.
Rome, travertins of, iv. 28.
Romney Marsh, gained from sea, i. 422.
Ronca, tertiary limestone of, iv. 211.
Ronchi, Roman bridge of, buried in

silt, i. 352.
Rose, M. G., on hornblende and augite,

ii. 178.
Ross, Captain, on icebergs in Baffin's

Bay, i. 172.
Rossberg, slide of the, iii. 200.
Rotaro, Monte, structure of, ii. 63.
Rotation of the earth, currents caused

by, i. 390.
Bother, River, vessel found in its old

bed, i. 423. ; iii. 247.
Roy at, near Clermont, iv, 200,

Royle, Mr., i. 152.

Rozet, M., on loess of the Rhine, iv. 38.

Runn of Cutch described, ii, 198.
Runton, crag strata in cliffs near, iv. 83.
Rye formerly destroyed by sea, i. 423.

Sabine, Captain, on well at Chiswick, *.

303.

— . on distance to which waters of
Amazon discolour the sea, ii. 33.

., on current crossing the mouth of
the Amazon, ii. 33.

Sabrina, island of, ii. 145. 205.

Saco, flood on the River, i. 293.

Saharunpore, buried town near, iii. 199.

St. Andre destroyed by a landslip, iii.

200

St. Andrews, loss of land at, i. 401.

, a gun -barrel, fossil, with shells at-
tached to it, near, iii. 250.

St. Christopher's, alternations of coral
and volcanic substances in, iv. 22.

St. Domingo, subsidence of coast of, ii.

255.
. , hot springs caused by earthquake

in, ii. 250.

, fossil vases, &c. in, iii. 246.

St. Eustatia, tertiary formations in, iv.

22.
St. George, banks of, i. 384.
St. Helena, tides at, i. 381.
St. Hospice, tertiary strata of, iv. 25.
St. Jago, earthquake at, ii. 189.
St. Katherine's Docks, a fossil vessel

found in, iii. 247.
St. Lawrence, Gulf of, elevated beaches

in, ii. 47. ; iv. 20.
, earthquakes in, ii. 208.

St. Madeleine, near Nice, fossil shells of,

iv. 66.
St. Maura, earthquakes in, ii. 194. 214.
St. Michael, siliceous springs of, i. 327.
St Michael's Mount, i. 430. ; iv. 368.
St. Mihiel, limestone cliffs of, iv. 20.
St. Ouen, five sheets of water intersected

in a well at, i. 306.
St. Peter's Mount, Maestricht, fossils of,

iv. 271.

St. Romain, gypsum of, iv. 154.

St. Sebastian overflowed by volcanic al-
luvions, ii. 94.

St. Ubes engulphed by earthquake, ii.

253.

INDEX.

437

St. Vincent's, volcanos of, ii. 203. ; r iv. 22.

, counter currents in the air proved

by eruption in, i. 188.
, boa constrictor conveyed on drift-

wood to, iii. 51.

Salisbury Craig, altered strata in, iv. 365.

Salt, on its deposition in the Mediter-
ranean, ii. 15.

Salt springs, i. 30. 330.

Saltholm, island of, ii. 288.

Samothracian deluge, ii. 52.

San Ciro, fossils in cave of, iv. 41.

Sand, estuaries blocked up by blown, i.

408. ; ii. 21.

•, cones of, thrown up during earth-
quake, ii. 235.

, drift, imbedding of towns, organic
remains, &c. in, iii. 188. 190.
Sanda, its promontory cut off by the sea,

i. 399.
Sandown Bay, excavated by sea, i. 425.

Sandstone, old red, fish found fossil in,

i. 234. 241.
Sandwich Land, perpetual snow to level

of sea-beach in, i. 175.
San Feliu de Paller61s, ravine in lava

near, iv. 96.
San Filippo, travertin of, i. 316.
Sanguinolaria rugosa, range of, iii. 56.
San Lio, on Etna, fissures in plain of, ii.

116.
San Lorenzo, isle of, recent fossils in, iv.

17.
San Lucido, torrents of mud caused by

earthquake at, ii. 234.

Santa Croce, Cape of, limestone on lava

at, iii. 390.
Santa Madalena, section at, iv. 93.

Santa Margarita, crater of, iv. 94.

Santa Maria, island, of raised 10 feet, ii.

187.
Santorin, geological structure of, ii. 160.
, chart and section of, ii. 161.
., new islands in Gulf of, ii. 162.
San Vignone, travertin of, i. 313.
Saracens, learning of the, i. 29.
Sardinian volcanos, iv. 101.,
Sasso, Dr., on tertiary strata of Genoa,

iv. 64.

, on fossil shells of Albenga, iv. 65.

Saucats, freshwater limestone of, iv. 134.
Saussure on the Alps and Jura, i. 80.

on glaciers of Mont Blanc, i. 259.

Savanna la Mar, swept away by sea, iii.

199.
Savona, tertiary strata of, iv. 140.

Saxony, Werner on the geology of, i.

83.
Scandinavia represented as an island by

the ancients, ii. 287.
., gradual rise of, i. 217. ; ii. 286. 340. ;

iii. 435. ; iv. 24.
See Sweden.
Scarpellini, Professor, i. 100.
Scheuchzer, his theory, 1708, i. 58.
Scheveningen, waste of cliffs of, ii. 5.
Schist, siliceous, clay converted into, by

a lava dike, iii. 392. 404.
Schlegel, M. de, i. 24.

Schmerling, Dr., on cavern of Chockier,
iii. 211.

on human remains in caves, iii. 212.

Sciacca, island of. See Graham Island.
Scilla on organic remains, 1670, i. 42.
Scilla, rock of, ii. 236.
Scoresby, Captain, on the gulf stream,

i. 171.
•, on the formation of field ice, i. 191.

■, on weight of rocks transported by

icebergs, i. 270. ,

., cited, iii. 41. 219. ; iv. 360.

Scotland, floods in, i. 266. ; iii. 232.

., fossil fish in old red sandstone of,

i. 235. ; iv. 296.

— , waste of coast of, i. 400.

— , slight earthquakes felt in, ii. 60.

— , thickness of alluvions in, ii. 241. .

— , peat-mosses of, iii. 179. 185.

., marl-lakes of, iii. 236. 259. 265.

•, granite veins of, iv. 339.
Scrope, Mr. G. P., on eruption of Vesu-
vius in 1822, ii. 80.

', on columnar basalts of Vesuvius,

ii. 90.
, on formation of pisolitic globules at

Pompeii, ii. 97.
•, on eruption of Etna in 1811, ii. 121.

., on advance of lava of 1819, ii. 122.

*, on cause of convexity of plain of
Malpais, ii. 135.

, on elevation craters, ii. 152.
— , on volcanic district of Naples, iv.

11.
, on volcanos of the Rhine, iv. 10 .

., on geology of Auvergne, iv. 185,

186. 194. 197.
Sea does not change its level, but land,

i. 26.
, Moro on manner in which it ac-
quired its sal tn ess, i. 62.

., its influence on climate, i. 174.

, area covered by, i. 221.

438

INDEX.

Sea, its encroachment on different

coasts, i. 392. 402. 431.
, cause of its rise and retreat during

earthquakes, ii 254.
Sea-cliffs, successive elevations proved

by, iii. 440.

, manner in which the sea destroys
successive ranges of, iii. 440. ; iv. 229.
— , ancient, in the Morea, iv. 19.

, in Peru, iv. 17.

Seaford, waste of cliffs at, i. 424. ; iv.
256.

Seals, migration of, iii. 45.

Sea- water, density of, i. 172.

Sea-weed, banks formed by drift, iii. 16.
265.

Seckendorf, M. de, on greywacke* slate,
with organic remains in granite, i. 84.
Secondary rocks, iii. 319. ; iv. 268.

of Weald Valley, iv. 222.

., their rise and degradation gradual,
iv. 251.
■, fossils of the, i. 157. 231.
, no species common to tertiary and,
iv. 272. 274. 279.

., circumstances under which they
originated, iii. 319.

, why more consolidated and dis-
turbed, iv. 316. 318.
., volcanic, of different ages, iv. 319.

Secondary freshwater deposits, why rare,

iv. 313.
Secondary periods, duration of, iv. 280.
Sedgwick, Professor, en the Hartz moun-
tains, i. 84.

— , on tertiary deposits of the Alps, i.
210.
-, on raised beaches in Ireland, i. 216.
, on Caithness schists, i. 235.
— , on magnesian limestone, i. 318.
— , on the antagonist power of vegeta-
tion, iii. 159.
, on preservation of organic remains

in fissures, iii. 208.
— , on diluvial waves, iii. 431 ; iv. 205.
-, on tertiary formations of Styria,

iv. 129. 131. 142.

— , on Isle of Wight, iv. 216. 260.
— , on transition rocks, iv. 300. 306.
■, on granite veins, iv. 340.

•, on cleavage and jointed structure
of rocks, iv. 354.

>, on garnets in altered shale, iv. 365.
Sediment, its distribution in the Adri-
atic, i. 352.

in river water, i. 366.

Sediment of Ganges compared to lavas

of Etna, i. 369.
— , rate of subsidence of some kinds of,

ii. 34.
— -, area over which it may be trans-
ported by currents, ii. 34.
Sedimentary deposition, causes which

occasion a shifting of the areas of, iii.

345.
rocks, distinction between volcanic

and, iii. 313.
Selside, fissure in limestone at, iii. 208.
Seminara, effects of earthquake near,

ii. 225. V

Seneca on a future deluge, i. 23.
Septaria of London clay described, iv,

214.

Serapis, temple of, ii. 267.

, ground plan of environs of, ii. 267.

, date of its re-elevation, ii. 278.

Serre del Solfizio, buried cones in cliffs
of, iii. 415.

, dikes at the base of, iii. 418.

Serres, E. R. A., on changes in brain of
foetus in vertebrated animals, ii. 439.

Serres, M. Marcel de, on changes in bu-
ried human bones, iii. 214-

, on human remains in French

caves, iii. 213. 215.

, on drifting of land shells to the

sea, iii. 360.

— , on tertiary strata of Montpellier,

iv. 126.
-, on fossil insects of Aix, iv. 210.

Seven Sleepers, legend of the, i. 119.

Severn, tides in estuary of, i. 382.

, gain of land in its estuary, i. 430.

Shakspeare cited, i. 233.

Shakspeare's cliff decays rapidly, i.
419.

Shales, bituminous, i. 335.

Sheep, multiplication of, in South Ame-
rica, iii. 115.

Shell marl, fossils in, iii. 259. 300.

Shells. See Testacea.

Sheppey, fossils of, i. 243.

, waste of the cliffs, i. 415.

Sherringham, sections in cliffs of, iv. 84.

, waste of cliffs at, i. 405. ; iv. 236.

Shetland Islands, action of the sea on,

i. 392. ; iv. 45.

« , rock masses drifted by sea in, i. 393.

, effect of lightning on rocks in,

i. 394.

•, granites of different ages in, iv.
343.

INDEX.

439

Shetland Islands, passage of trap into

granite in the, iv* 349.
, formations now in progress near,

iii. 272.

Shingle beaches, i. 428.

Ships, number of British, wrecked annu-
ally, iii. 240. 243.
., fossil, i. 423. ; iii. 188. 246.

Shropshire coal-field, i. 202.
Sibbald cited, iii. 50. 266.
Siberia, rhinoceros found entire in the
frozen soil of, i. 80. 150.
., the Bengal tiger found in, i. 147.

, Lowland of, i. 153. 219.

, drift-timber on coast of, iii. 224.

Siberian mammoths, i. 144.
Sicily, fossils of existing species in, i. 140.
., earthquakes in, ii. 54. 208. 261. ;

iii. 207.

— , geological structure of, iii. 340. 383.

., map of part of, iii. 382.

., origin of newer Pliocene strata of,

iii! 433.
., form of valleys of, iii. 438.
., no peculiar indigenous species

found in, iii. 445.
. — , caves in, iv. 38.
., alluviums of, iv. 48.
Sidon, ancient site of, two miles from

sea, ii. 31.
Siebengebirge, volcanic rocks of the, iv.

36. 109.
Sienna, fossil shells of, i. 68. 141. ; iv. 74.

, Subapennine strata near, iv. 55. 60.

Silex deposited by springs, i. 327.

t% piles of Trajan's bridge said to be

converted into, i. 329.
Silla, subsidence of the mountain, ii.

202, 203.
Silliman, Professor, cited, in. 247.
Silurian group of rocks, iv. 270. 298.
Silvertop, Colonel, on tertiary strata of

Spain, iv. 70.
Simeto, R., lava excavated by, i. 272.

plain of the, iii. 399.

Sindree, changes caused by earthquake

of 1819 near, ii. 196. ; iii. 254.
9 view of the fort of, before the

earthquake {see PI. 6.), ii. 196.
Sioule, R., ravines cut through lava by,

iv. 194.
Sipparah, R., its course changed, iii. 194.
Skapta, R., its channel filled by lava, ii.

128.
Skaptar Jokul, eruption of, ii. 128.

Sky granite of, iv. 343.

354.

Slate rocks, cleavage planes of, iv.
Slave Lake, drift-timber in, iii. 221.
Sleswick, waste of coast of, ii. 8.
Sligo, bursting of a peat-moss in, iii. 186.
Sloane, Sir H., on earthquake in Ja-
maica, ii. 264.

, on dispersion of plants, iii. 214.

Smeaton on effect of winds on the sur-
face of water, i. 386.
Smith, William, agreement of his sys-
tem with Werner's, i. 84.

., his < Tabular View of the British
Strata,' 1790, i. 102.
., his Map of England, i. 103.
., priority of his arrangement, i. 103.
Smith, Sir J., cited, ii. 401. ; iii. 19.
Smyrna, volcanic country round, ii. 54.
Smyth, Capt. W. H., on the Mediterra-
nean, i. 78. 348. ; ii. 272.
., on height of Etna, ii. 111.
., on Straits of Gibraltar, ii. 15. 18.
— , on depth of sea from which Gra-
ham Island rose, ii. 146.
., on floating islands of drift-wood,

iii. 43.
-, on drifting of birds by the wind,

iii. 49.

., on diffusion of insects, iii. 66.
on average number of British
ships lost from 1793 to 1829, iii. 243.

., found shells at great depths be-

tween Gibraltar and Ceuta, iii. 271.
., on volcanos of Sardinia, iv. 101.

Snow, height of perpetual, in the Andes,

i. 194.
, m Himalaya mountains, i. 194.

Sodertelje, canal of, ii. 294.

9 recent strata of, ii. 300.

■ ', buried hut in, ii. 303.

Sodom, catastrophe of, mentioned by

Hooke, i. 51.
Soil, its influence on plants, ii. 402.
Soils, on formation of, iii. 155.
influence of plants on, iii. 87.

Soldani, theory of, 1780, i. 78.

on microscopic testacea of Medi-
terranean, i. 78.

on the Paris basin, i. 78.

Solenhofen, fossils of, iv. 289.
Solent, its channel widening, i. 425.
Solfatara, lake of, i. 320.

., volcano, ii. 65. 70. 74. 78.

effects of the exhalations on its

structure, ii. 90. ; iv. 374.

, temple of Serapis probably sub-
merged during eruption of, ii. 279.

440

INDEX.

Solon on Island of Atlantis, i. 14.

Sol way Moss, a man and horse, in ar-
mour, found in, iii. 186.

, bursting of, iii. 186.

Solway Firth, animals washed by river-
floods into, iii. 232.

Somersetshire, land gained in, i. 430.

Somerville, Mrs., on depth of Atlantic
and Pacific Oceans, i. 185.

., on effects of compression at earth's
centre, ii. 312.

Somma, escarpment of, iii. 410, 411. 414.
425.

, dikes of, ii. 88. ; iv. 5.

,- changes caused by dikes in, iii.

418.

and Vesuvius, differences in com-
position of, iv. 4.
, section of, ii. 87.

Somme, peatmosses in valley of, iii. 187.
Sorbonne, College of the, i. 69.
Sorea, eruption in island of, ii. 261.

Soriano, changes caused by earthquake
near, ii. 219. 230.

Sortino, limestone formation in valleys
of, iii. 385.

, caves near, iv. 39.

Sortino Vecchio, several thousand peo-
ple entombed at once in caverns at,
iii. 207.

South Carolina, earthquake in, ii. 203.
South Downs, waste of plastic clay on,
i. 424.

, chalk ridge called the, iv. 223.
, section from, to the North Downs
across Weald Valley, i v. 224.
, highest point of, iv. 224.

, section from, to Barcombe, iv. 234.

, on former continuity of chalk of

North and, iv. 244.
Souvignargues, cave at, iii. 214.
Spaccaforno limestone, iii. 386.
Spada, his theory, i. 60.
Spain, earthquakes in, ii. 57.

, tertiary formations of, iv. 70.
•, extinct volcanos of, iv. 90,
lavas excavated by rivers in, iv.
93. 97.

Spallanzani on effects of heat on seeds
of plants, iii. 14.

on flight of birds, iii. 48.
Species, definition of the term, ii. 361.
, Linmeus on constancy of, ii. 363.
, Lamarck's theory of transmut-
ation of, ii. 363. 386. ;"iii. 139.
», reality of, in nature, ii. 391. 407. 441.

Species, geographical distribution of, iii.
1. 371.

-, theories respecting their first in-
troduction, iii. 77. 145.

», Brocchi on extinction of, iii. 83.

•, reciprocal influence of aquatic and
terrestrial, iii. 98.
— , their successive destruction part

of the order of nature, iii. 101. 132.
142. 150.

■, effect of changes in geography,

climate, &c. on their distribution, i.
182. ; iii. 122. 134. 138. 331. 350.
-, superior longevity of molluscous,

i. 145. ; iii. 361. ; iv. 40.

•, necessity of accurately determin-
ing, iii. 361.

, living, proportion of, in different

tertiary periods, iii. 369. 373.

in Sicily older than country they

inhabit, iii. 445J

-, none common to secondary and

tertiary formations, iv. 272. 274.
Spence, Mr., on insects, cited, ii. 433. 5

iii. 63. 93.

Spina, ancient city in delta of Po, i, 351.

Spinto, fossil shells at, iv. 127.

Spitzbergen, glaciers of, i. 172.

Spix, M., on drifting of animals by the
Amazon, iii. 42.

, on Brazil, iii. 108.

Spontaneous generation, theory of, i. 38.
Sprengel, M., on numbers of plants, iii.
148.

Springs, origin of, i. 300.

s the theory of, illustrated by bored

wells, i. 302.

most abundant in volcanic regions,

i. 309.

affected by earthquakes, i. 309. ; ii

188. 228. 250.

— , transporting power of, i. 136. 311.

., calcareous, i. 311. 325.

-, sulphate of magnesia deposited by,

i. 316.

— , sulphureous and gypseous, i. 326.

■, siliceous, i. 327.

-, ferruginous, i. 330.

■, brine, i. 330.

, carbonated, i. 331.

, petroleum, i. 334.

Spurn Point, its rapid decay, i. 403.
Squirrels, migrations of, iii. 36.
Stabize, buried city of, ii. 106.

Stalagmite alternating with alluvium in
caves, iii. 210.

INDEX.

441

Start Island separated from Sanda by

sea, i. 399.
Statical figure of the earth, ii. 309. 329.
Stations of plants, description of, iii. 5.

of animals, iii. 100.

Staunton, Sir G., on sediment in Yellow

River, i. 366.

Staveren, formation of Straits of, i. 421. ;

ii. 6. ; iii. 130.
Steele on Burnet's theory, i. 56.
Steininger, M., on loess of the Rhine,

iv. 34. 38.

., on volcanic district of the Eifel,iv.
113

, on grey wacke rocks , i v. 299.

Stelluti on organic remains, i. 39.
Steno, opinions of, i. 40.
Stephensen on eruption in Iceland, ii. 127.
Steppes, Russian, geology of the, ii. 51.
Sternberg, Count, on the coal strata, i.

202. •

Stevenson, Mr., on drift stones thrown

on the Bell Rock, i. 400.
, on the German Ocean, i. 420. ; ii.

29/
, on waste of cliffs, i. 431.

Stewart, Dugald, cited, i. 249.

Steyning, chalk escarpment above, iv.

223.

Stirling Castle, altered strata in rock of,
iv. 365.

Stockholm, rise of land near, ii. 294.
, upraised deposits of shells near, ii.

299.301.
Stonesfield, fossils of, i. 237. ; iv. 290.
Storm of November, 1824, effect of, i.

424. 426. 428.
Stour and Avon, cliffs undermined, i.

426.

Strabo cited, i. 24. 346. 354. ; ii. 56. 62.

Straits of Dover, formation of, i. 420.

, their depth, i. 420, 421.

Straits of Staveren, formation of, i. 421. 5

ii. 6,
Straits of Gibraltar, currents in, &c,

ii. 14. 16. 20.

Stralsund, ii. 288.

Strata, cause of limited continuity of,

iii. 312.

, order of succession of, iii. 318.

., origin of European tertiary, at

successive periods, iii. 335.

.-, recent, form a common point of

departure in all countries, iii. 378.

, with and without organic remains
alternating, iv„ 181.

Strata, fossiliferous, classification of the,
iv. 269.

, on consolidation of, iv. SI 6.

Stratification in deltas, causes of, i. 376.
of debris deposited by currents, i.

378. ; ii. 36.

, unconformable, remarks on, iii.
349.

of the Crag, iv. 78.

of primary rocks, iv. 353.

, difference between cleavage and .

iv. 354.

Strato, hypothesis of, i. 25.
Stratton, Mr., on buried temples in
Egypt, iii. 189.

Strickland, Mr., on tertiary strata hear
Cropthorn, i. 145.

Strike of beds, explanation of term, iv.

332.

Stromboli, its appearance during Cala-

brian earthquakes, ii. 237.
, lava of, iv. 350.

Studer, M. , on molasse of Switzerland,
iv. 128.

, on theory of M. E. de Beaumont,

iv. 333.

, on altered strata in the Alps, iv.
370.

Stufas, jets of steam, in volcanic re-
gions, i. 308.

Stutchbury, Mr., on coral islands, iii.

279. 281, 282. 296.
Styria, tertiary formations of, iv. 128.

142.

Subapennine strata, i. 141. 209. 241. ; ii.

216. ; iv. 49.

, early theories of Italian geologists

concerning, i. 74. 127.
•, opinions of Brocchi on the, iv. 49.
, subdivisions of, described, iv. 53.
j how formed, iv. 56.
■, organic remains of the, iv. 59.
Subaqueous strata, imbedding of fossils
in, iii. 258.

■, our continents chiefly composed
of, iii. 313.

•, how raised, iii. 435.

•, distinction between alluvium and,

iii. 196.
Submarine forests, i. 400. 431. ; iii. 226.
Submarine peat, iii. 187. 2£5.
Submarine volcanos, ii. 145.
Subsidence of land, ii. 195. 201, 202. 208.

218. 233. 252. 256. 262. 268. 5 iii. 124.

252. 255. 295. 424.
, permanent, ii. 339.

442

INDEX.

Subsidence of land, greater than eleva-
tion, ii. 356. ; iii. 295.
Subterranean lava causes elevation of

land, iii. 436.
Successive development of organic life,

i. 227.
Suez, Isthmus of, ii. 31.

Suffolk, cliffs undermined, i. 410.

., inland cliff on coast of, i. 410.

., tertiary strata of, iii. 336. ; iv. 71.
Sullivan's Island, waste of, ii. 10.
Sulphur Island, ii. 48.
Sulphureous springs, i. 326.
Sumatra, volcanos in, ii. 49.
Sumbawa, subsidence in island of, 1815,

ii. 200. ; iii. 254.
Sunderbunds, part of delta of Ganges, i.

Sunderland, magnesian limestone of, i.

319.

Superga, fossil shells of the, iii. 364. ; iv.

126,
Superior, Lake, deltas of, i. 342.
, recent deposits in, i. 344 ; iii. 262.

-, its depth, extent, &c, i. 342. 344.

■, bursting of, would cause a flood,

iv. 201.
Superposition of successive formations,
causes of the, iii. 345.

, proof of more recent origin, iii. 320.

., exceptions in regard to volcanic
rocks, iii. 321.

-, no invariable order of, in Hypo-
gene formations, iv. 380.
Surface, state of, when secondary and

tertiary strata were formed, iii. 341.
Sussex, Weald formation of, i. 206.

., waste of its coast, i. 423.
Swanage Bay excavated by sea, i. 425.
Swatch in Bay of Bengal, i. 359.
Sweden, gradual rise of, ii. 286. 353. ; i.
217. ; iv. 24. 26. 251.

earthquakes in, ii. 304.
., lignite of chalk period in, iv. 278.
•> greywacke rocks of, iv. 300.

.. See also Scandinavia.
Swinburne, Capt, on Graham Island,

ii. 147. 150.

Switzerland, towns destroyed by land-
slips in, iii. 200.

— , « molasse ' of, iv. 128.

Symes on petroleum springs, i. 334r.

Syenites not distinguishable from gra-
nites, iv. 344.

Syracuse, section at, iii. 385.

., inland cliffs north of, iii. 440.
•, caves near, iv. 39.

Syria, gain of land on its coasts, ii. 31
, earthquakes in, ii. 54.

Table-Mountain, intersected by veins,

iv. 339.
Tacitus cited, ii. 68.
Tadeausac, earthquakes at, ii. 208.
Tagliamento, R., delta of the, i. 350.

, conglomerates formed by, i. 352.

Talcahuano, recent elevation of, ii. 187.
Tampico, sediment transported by, ii-

33.
Tanaro, plains of the, iii. 364. ; iv. 127^
Tangaran, R.,« stopped up by. landslips,

ii. 260.
Targioni on geology of Tuscany, i. 70.

■, on origin of valleys, i. 70.

•, on fossil elephants, i. 71.

., on deposits of springs, i. 313.

Taro, R., iv. 56.

Tay, encroachment of sea in its estuary,

i. 400.

Taylor, Mr., on art of mining in Eng-
land, i. 81.

Taylor, Mr. R. C, on waste of cliffs, i.

406.

• 9 on gain of land on coast of Nor-
folk, i. 408.

— , on the formation of Lowestoff

Ness, i. 410.
Tech, R., valley of, iv. 69.
Teissier, M., on human bones in caves,

&c, iii. 215.

Temminck cited, iii. 30. 149.

Temperature, great changes in, i. 163.

, difference of, in places in same la-
titudes, i. 167.

, causes of change in, i. 180.

. See Climate

Temples, buried, in Egypt, iii. 188.

Temruk, earthquakes near, ii. 53.

Teneriffe, its peak an active solfatara,

ii. 138.

- — , volcanic eruptions of, ii. 139.

Ter, R., valley of the, iv. 91.

Terni, limestone forming near, i. 319.

Teronel, R., lava excavated by, iv. 97-

Terraces, manner in which the sea de-
stroys successive lines of, iii. 440. ; i y

229.
Terranuova, subsidence near, ii. 208.

, fault in the tower of, ii. 219.

, landslips near, ii. 229.

-, tertiary strata at, iii . 396.

INDEX.

443

T 1

ertiary formations, general remarks on

the, i. 239. ; iii. 319.

, origin of the European, at succes-
sive periods, iii. 335.

, circumstances under which these
and the secondary formations may
have originated, iii. 342. ; iv. 308.

-, state of the surface when they

were formed, iii. 342.
., classification of, in chronological

order, iii. 356.
•, new subdivisions of the, iii. 362.
numerical proportion of recent

shells in different, iii. 369. 373.

— , mammiferous remains of succes-

sive, iii. 379.
-, Synoptical Table] of Recent and,

iii. 381.

identity of their mineral com-

position no proof of contemporaneous

origin, iv. 51.
., no species common to secondary

and, iv. 272. 274. 279.
., of Auvergne, iv. 134. 144.

England, iii. 335, 336. ; iv. 25

71. 211.
., of the Paris basin, iii. 332. ; iv. 164

., of Sicily, iii. 382.

., marine, iii. 332. 335. 383. 397. 433.

Thanet, Isle of, loss of land in, i. 418.
Theorizing in geology, different methods

of, iii. 3C3.
Thermo-electricity, ii. 324.

Thirria, M., cited, iv. 289.
Thompson, Dr., on siliceous incrust-
ations near Monte Vico, i. 329.
Thrace subject to earthquakes, ii. 56.
Thucydides on Etna, ii. 115.
Thun, Lake of, delta of the Kander in,

ivi 68.
Thury, M. Hericart de, on Artesian

wells, i. 303.
Tiber, growth of its delta, i. 321.

, valley of the, iv. 29.

Tide wave of the Atlantic, i. 409.
Tides, height to which they rise, i. 360.

381.
, effect of winds on the, i. 385.

, effects of, on wells near London,

i. 301.
-, their destroying and transporting

power, i. 380.
— , their reproductive effects, ii. 22.
and currents, drifting of remains

iv. 1. 49. 114. 164. 208.

-, freshwater, iv. 27. 137. 143.

., volcanic, iii. 389. 400. ; iv. 4. 89

140. 184.
Testa and Fortis on fossil fish of Monte

Bolca, i. 78.
Testacea, their geographical distribu-
tion, iii. 55.
., fossil, importance of, iii. 359.

., marine, imbedding of, iii. 269. 327.

359.
-, freshwater, iii. 265.

., burrowing, iii. 270.
., parasitic, iii. 283.
9 longevity of species of, i. 145. -, iii.

361. 372. ; iv. 40.
. recent, number of, in different ter-

tiary periods, iii. 369. 373.
Tet, valley of, tertiary strata in, iv. 69.
Texel, waste of islands at its mouth,

ii. 7.
Thames, gain and loss of land in its es-
tuary, i. 415.

., tide in its estuary, ii. 24.

., buried vessel in alluvial plain of

the, iii. 247.
., basin of the, iii. 335.

of animals by, iii. 237.

Tiedemann on changes in the brain in

the foetus of vertebrated animals, ii.

439.
Tierra del Fuego supposed to contain

active volcanos, ii. 41.
Tin" is, earthquakes at, ii. 53.
Tiger of Bengal found in Siberia, i.

146.
Tigris and Euphrates, their union a

modern event, i. 375.
Tiganux, tower of, i. 347.
Tilesius on Siberian mammoth, i. 153.
Time, prepossessions in regard to the
duration of past, i. 112. ; iii. 426.

•, error as to quantity of, fatal to
sound views in geology, i. 115.

, great periods required to explain
formation of sedimentary strata, i.

130.
Tivoli, flood at, i. 298.

■ , travertin of, i. 322.

Toledo, Signor, on elevation of coast of

Bay of Baiffi, ii. 282.
Tomboro, volcano, eruption of, ii. 200.

■ , town of, submerged, ii. 201.

Torneo, gain of land at, i. 345. ; ii. 289.
Torre del Annunziata, columnar lava

at, ii. 89.

Torre del Greco overflowed by lava, ii.

107.

444

INDEX.

Torre del Greco, columnar lavas of Vesu-
vius seen at, ii. 89.

Torrents, action of, in widening valleys,
i. 263.

Torum, overwhelmed by sea, ii. 8.

Tory Island, living testacea at great
depths off, iii. 271.

Totten,*Col., on expansion of rocks by
heat, ii. 339.

Touraine, tertiary strata of, iii. 337.: iv.
115.

Tournal, M., on French caves, iii. 213.
215.

Tours, shells, &c. brought up in a bored
well at, i. 307.

Towns destroyed by landslips, iii. 200.
Trade winds, i. 188. 389.
Traditions of losses of land, i. 430, 431.
Transition formations, fossils of, i. 201.
234,. : iv. 297.

, their extent, i. 200. See Grey-

wacke.

Transverse valleys in North and South
Downs, iv. 238.

Transylvania, tertiary formations of,iv.

129. 131. 142.
Trap rocks, origin of the term, iv. 346.

, passage of, into granite, iv. 348.

Trass of Rhine volcanos, iv. 108.

Travertin of the Elsa, i. 312. ; iv. 27.
of San Vignone, i. 313.
of San Filippo, i. 316.
•, spheroidal structure of, i. 317.
., compared to the English magne-
sian limestone, i. 318.
— of Tivoli, i. 322.

oolitic, recent formation of, in Lan-
cerote, ii. 144.

in Forfarshire, iii. 259.

of Rome, fossils in x iv. 28.
Trees, longevity of, iii. 428. ; iv. 205.
Trezza, travertin formed by spray of the
sea on rocks of, ii. 144.

., Bay of, sub-Etnean formations in
the, iii. 401.

■, submarine eruptions in, iii. 401.

405.
Trimmer, Mr., on recent marine shells

in Wales, i. 215.
Trimmingham, sections near, iv. 77. 86.
Trinidad, subsidence in, i. 334.

, pitch lake of, i. 334.

earthquakes in, ii. 250.

Tripolitza, plain of, breccias forming in,

iii. 205.

Trollhattan, ii. 343. I

Truncated volcanic cones, ii. 167. 249.
Tubal, elevation of land at, ii. 188.
Tufa. See Travertin. '

Tuff, dikes of, how formed, iii. 392.

, shells in, iv. 11.

Tunguragua volcano, ii. 43, 44. 206.
Tunza, R., ii. 189.

Turin, tertiary formations of, iv. 126.
Turtles, migrations of, iii. 50.

, eggs of, fossil, iii. 267.

Turton cited, iii. 41. 51.
Tuscany, geology of, i. 40. 70.

, calcareous springs of, i. 312.

, freshwater formations of, iv. 27-

, volcanic rocks of, iii. 365. ; iv. 89

Tyre now far inland, ii. 31.
Tyrol, Dolomieu on the, i. 87.

Uddevalla, upraised deposits of shells at,
ii. 299.

Ullah Bund, formation of the, ii. 197-
Ulloa cited, ii. 257. : iii. 115.
Unalaschka, new island near, ii. 205.
Unconformability of strata, remarks on
the, iii. 349.353.

Uniformity of Nature, i. 128. 255. ; ii.
75.

Universal formations of Werner, i. 84.

remarks on theory of, iii. 323. : iv.
315.

Universal ocean, theory of an, i. 46. 60.

disproved by organic remains, i.137.

Upsala, strata near, ii. 301.
Urmia, Lake, springs near, i. 326.
, its size, &c„ ii. 54.

Val d'Arno, Upper, lacustrine strata of,

iv. 57. 137.

, fossils of the, i. 242. ; iv. 138.

, effect of destruction of ft in,

iii. 163.

Val del Bove on Etna described, iii.
407. 413.

, section of buried cones in, iii. 415.

•, form, composition, and origin of
the dikes in, iii. 414. 417.

lavas and breccias of the, ii. 121. ;

iii. 422.
— , origin of the, iii. 423.
., floods in, ii. 123. ; iii. 425.

■

INDEX.

445

Valdemone, formations of, iii. 397.
Val di Calanna, its shape, &c, iii. 411.°

/began to be filled up by lava in 1811

and 1819, ii. 122. ; iii. 413.
Val di Noto, Dolomieu on the, i. 87.
■, formations of the, iii. 383.
., volcanic rocks of the, iii. 384. 389.;
iv. 347.
., volcanic conglomerates of, iii. 396.
■, form of valleys of, iii. 438.
, inland cliffs on east side of, iii.
440.
"Vale of Pewsey, iv. 250.
Valle das Furnas, hot springs of, i. 327.
Valley of the Nadder, iv. 250.
Valleys, Targioni on origin of, i. 70.
', excavation of, in Central France,
i. 272.

of elevation, ii. 176. ; iv. 246.
on Etna, account of, iii. 407.
of Sicily, their form, iii. 438.
, the excavation of, assisted by
earthquakes, ii. 237. ; iii. 442.

■, transverse, of North and South
Downs, iv. 238, 239.

of S. E. of England, how formed,

iv. 263.
Vallisneri on origin of springs, i. 59.
on marine deposits of Italy, i. 59.
on the danger of connecting theo-
ries in physicaljscience with the sacred
writings, i. 59.
., universal ocean of, i 60.
on primary rocks, i. 91.
Valmondois, tertiary strata of, iv. 173.
Valognes, tertiary strata of, iv. 208.
Valparaiso, changes caused by earth-
quakes at, ii. 189. 192. 278. ; iii. '253.
Van der Wyck, M., on the Eifel. iv.

113.
Van Diemen's Land, climate of, i. 175.

Var, R., gravel swept into sea by, iv.

65.68.
Vatican, hill of the, tufa on > iv. 28.
Veaugirard, alternation of calcaire gros-

sier and plastic clay at, iv. 168.
Vegetable soil, why it does not increase,

iii. 155.

, how formed, iii. 157.

Vegetation, centres of, iii. 144.

, its conservative influence, iii. 158.

162.

, its influence on climate, iii. 165.

Veins, mineral, on their formation, ii.

227. 5 iv. 373.

of lava. See Dikes.

Velay, extinct quadrupeds in volcanic
scoria? in, iv. 136. 190.
•, freshwater formations of, iv. 157.
•, volcanic rocks of, iv. 142. 188. 190.
Vera Cruz destroyed by earthquake, ii.
259.

Verdun, markings on cliffs near, iv. 20.
Verona, fossils of, i. 34. 38. 60.

, Arduino on mountains of, i. 72.

Vertebrated animals in oldest strata, i.

237.
Vessels, fossil. See Ships.
Vesta, temple of, i. 299.
Vesuvius, excavation of tuff on, i. 272.
, history of, ii. 66. 79.

., eruptions of, ii. 66. 77. 79. ; iii. 424.

-, dikes of, ii. 85. ; iv. 5. 7.

., lava of, ii. 89. 94.

., volcanic alluvions on, iii. 192.

and Somma, difference in their
composition, iv. 4.

., probable section of, ii. 86.
Vicentin, Dolomieu on the, i. 87.
., submarine lavas of the, i. 128.

, tertiary strata of the, iv. 211.

Vicenza, mountains of, i. 72.

Vichy, tertiary oolitic limestone of, iv.

152.
Vidal, Captain, on Rockall bank, iii.

271.
Vienna, gypseous springs of, i. 23.

., tertiary formations of, iii. 339. ; iv
128.

Vigolano, gypsum and marls at, iv. 54.
Villages and their inhabitants buried by

landslips, iii. 200.
Villarica volcano, ii. 42.
Villasmonde, limestone of, iii. 385.
Villefranche, Bay of, strata near, iv. 25.
Vinegar R., sulphuric acid, &c. in waters

of, iv. 178.
Virgil cited, i. 249.

Virlet, M., on deluge of Samothrace, ii.
53.

«, on volcanos of Greece, ii. 56.

-, on greywacke" fossils, i. 201.

, on island of Santorin, ii. 161. 165,
166.

■, on corrosion of hard rocks by sub-
terranean gases, iii. 202. ; iv. 374.

-, on imbedding of human bones in
the Morea, iii. 205.

., on geology of the Morea, iv. 70.

277.
Viterbo, travertin of, i. 319.

, tuffs and marls at, iv. 54. §

^^M

*HJ

446

INDEX.

Viterbo, volcanic rocks of, iv. 89.
Vito Amici on Moro's system, i. 67.
Vivarais, basalts of the, i. 86.
Vivenzio on earthquake of Calabria in

1783, ii. 212. 233.
Viviani, Professor, on Sicilian flora,

iii. 444.
, 9 on tertiary strata of Genoa, iv.

64.

Vizzini, tuff and limestone near, iii.

392.

., changes caused by a dike of lava
at, iii. 392.

•, oyster-bed between two lava cur-
rents at, iii. 395.
Volcanic action, defined, ii. 39.

, uniformity of, iii« 161.

Volcanic breccias, how formed,, iv. 117.
Volcanic cones, truncation of, ii. 167.

249.
., their perfect state no proof of their

relative age, iii. 164.

Volcanic conglomerates, iii. 396.

Volcanic dikes. See Dikes.

Volcanic eruptions, causes of, ii. 320.

, average number of, per annum, ii.

178.
Volcanic formations, fossils in, iii,

191.
Volcanic lines, modern, not parallel,

iv. 333.
Volcanic products, mineral composition

of, ii. 177.
Volcanic regions, their geographical

boundaries, ii. 41.
, map showing extent of (see

Plate 3.), ii. 47.
Volcanic rocks, subterranean, ii. 179.
, distinction between sedimentary

and, iii. 313.

— , distinction between plutonic and,

iv. 345.

— , age of, how determined, iii. 321.

of the Val di Noto, iii. 389.
of Campania, iv. 1.
- of Italy, iv. 89.
of Hungary, Transylvania, and

Styria, iv. 140.

of Central France, ii. 170. 175. ; iv.

184.

— secondary, of many different ages,

iv.319.

Volcanic vents, remarks on their posi-
tion, ii. 40. 347.

Volcanos, safety valves according to

Strabo, i. 27.

Volcanos, duration of past time proved
by extinct, i. 132.

-, agency of water in, ii. 347.
— , mode of computing the age of,

iii. 426.

sometimes inactive for centuries,

iii. 427.

— the result of successive accumu-

lation, iv. 162.

Volhynia, tertiary formations of, iv. 132,

Voltaire, his dislike of geology, i. 96.

on systems of Burnet and Wood-
ward, i. 96.

Volterra, Mattani onTfossils of, i. 60.

Voltz, M.,on loess of the Rhine, iv. 38.
Von Buch on rise of land in Sweden,

i. 216. ; ii. 292. 299.

on volcanos of Greece, ii. 56.

on eruption in Lancerote, ii. 139.

», his theory of elevation craters con-
sidered, ii. 152.

on volcanic rocks, ii. 175.

on new island near Kamtschatka,

ii. 205.

— on the Eifel, iv. 126.

on tertiary formations of Volhynia

and Podolia, iv. 132.

on volcanic lines, iv. 333.

Von Dechen, M., on volcanic district of

Lower Rhine, iv. 113.
., on the Hartz mountains, iv. 332.

, on granite veins, iv. 339.

Von Hoff. See Hoff.

Von Oeynhausen on the Eifel district,

iv. 102. 113.

on granite veins, iv. 339.
Vosges, loess near their base, iv. 30.
Vulcanists, persecution of, in England,

i. 98.
Vulcanists and Neptunists, factions of,

i. 88.
Vultur, Mount ,Ti i. 57.
Vultures, range of, iii. 46.

Waal, R., ii. 3, 4. ".

Wahlenberg, Professor, on greywack£

of Sweden, iv. 300.
Wales, slate rocks of, iv. 354. 382.
Wallerius, theory of, i. 79.
Wallich, Dr., on Ava fossils, i. 50.
Walton, sections near, iv. 78. 80.
Walton Naze cliffs, undermined, i. 415.
Warburton, Mr., on Bagshot sand, iv

215.

INDEX.

447

Ward, Mr., on Kentucky caves, iii. 202.
Warp of the H umber, i. 377. ; ii. 27.
Warton, his eulogy on Burnet, i. 56.
Washita, R., raft on, i. 286.
Water, action of running, i. 261.
., its power on freezing, i. 262.
., solvent power of, i. 262.
, excavating power of, i. 263.
, transporting power of, i. 264.
, agency of, in volcanos, ii- 347.
., absorption of carbonic acid by, iv.
372.
Watt, Gregory, his experiments on

rocks, iv. 9. 370.
Weald, denudation of valley of the, iv.
221. 259.
■, secondary rocks of the, iv. 222.
•, section of valley of the, iv/ 223,
224.

-, alluvium of valley of the, iv. 234.

Wealden, secondary group, called the,

iv. 280.
., organic remains of the, iv. 281. 286.

, its extent, thickness, &c, iv. 308.

Weaver, Mr., on coal of Munster, i. 201.
Webb, Mr., on the Great Canary, ii. 158.
Webster, Dr., on hot springs of Furnas,

i. 328.
Webster, Mr., on waste of Sussex cliffs,

i. 423.
— ~, on geology of I. of Wight, iii. 335. ;
iv. 253. 260.

•, on formations of London and
Hampshire basins, iv. 213. 215.
., on fossil forest of I. of Portland,

iv. 284.
Weddell, Captain, latitude reached by,

1. I/O.

Wellington Valley, Australia, fossils in

breccias in, iv. 43.
Wells, influence of the tides on, near
London, i. 301.

, Artesian, i. 302.

Wener, Lake, strata near, ii. 300.
Wenlock rocks, iv. 270, 271. 298.
Werner, Professor of Mineralogy at
Freyberg, 1775, i- 81.
., his lectures, i. 83.
, universal formations of, i. 84.
on granite of the Hartz, i. 84.
■, principal merit of his system, i. 84.
, his theory of basalt, i. 85.
, taught that there were no volcanos
in the primeval ages, i. 85.
-, technical terms of, i. 103.
, on transition rocks, iii. 318.

West Indies, Hooke on earthquake in,
i. 51.

, active volcanos in, ii. 46.

■ , tertiary formations of, iv. 21.

Wey, transverse valley of the, iv. 238.

Whales stranded, iii. 266.

Whewell, Rev. Mr., on modern progress

of geology, i. 105.

, on the tides, ii. 10.

, cited, i. 185. ; iii. 369.

Whirlwinds, violent, during eruption in

Sumbawa, ii. 200.

, dispersion of seeds by, iii. 11.

Whist on, his Theory of the Earth, i. 56.
■ , refuted by Keill, i. 58.

White Mountains, landslips in the, i.
293.

Whitehurst, theory of, 1778, i. 79.

, on rocks of Derbyshire, i. 79.

, on subsidence at Lisbon, ii. 252.

Whitsunday Island, description of, iii.

286.
Wiegmann on hybrids, ii. 425, 426.
Wildon, coralline limestone of, iv. 130.
Willdenow on diffusion of plants by

man, iii. 23.
on centres of vegetable creation,

iii. 144.
Williams on Hutton's theory, i. 98.
Wiltshire, valleys of elevation in, iv,

249.
Wily, valley of the, iv. 250.
Winchelsea destroyed by sea, i. 423.

Winds, trade, i. 188. 389.

, currents caused by the, i. 385.

, sand drifted by the, ii. 21.
Wismar, ii. 288.
Wodehouse, Captain, on Graham Island,

ii. 147.
Wokey Hole, human remains in, iii. 212.

Wolf, and dog, distinct species, ii. 395.

, hybrids between the, ii. 424.

drifted to sea on ice, iii. 41.
extirpated in Great Britain, iii.

110.
Wollaston, Dr., on water of Mediter-
ranean, ii. 15.

, cited, ii. 112.

Wood, Mr., on fossils of the Crag, iv.

72. 74.
Wood impregnated with saltwater when

sunk to great depths, iii. 219.
, drift, i. 161. 284. 287. 365. ; iii. 41.

221.

converted into lignite, iii. 248.

Woodward, theory of, i. 54. 59. 96. 118.

*^H

448

INDEX.

Wrecks, average number of, per year,

iii 240. 242.
Wrotham Hill, height of, iv. 224.

Xanthus, the Lydian, his theory, i. 25.

Young, Dr., on effects of compression at

earth's centre, ii. 312.
Ytrac, freshwater flints at, iv. 159.

Yaou, flood of, i. 10.

Yarmouth, estuary silted up at, i. 407.

, rise of the tide at, i. 381. 407.

, strata near, iv. 77.

Yates, Rev. J., on delta of the Kander,

iv. 69.
Yellow R., sediment in, i. 366.

Yenesei R., fossil bones on banks of, i
148.

Yorkshire, bones of mammoth in, i. 145.

, waste of its coasts, i. 402.

, chalk of, iv. 256.

Zaffarana, valleys near, iii. 410.
Zante, earthquakes in island of, ii. 214.
Zechstein formation, iv. 293.
Zingst peninsula converted into an is-
land, ii. 12.

Zocolaro, hill of, lava of Etna deflected

from its course by, iii. 413.
Zoological provinces how formed, iii. 79.
, why not more blended together,

iii. 82.

?great extent of, iii. 325.

Zoophytes, their geographical distribu-
tion, iii. 61.

, their powers of diffusion, iii. 61.^

, abundance of, iii. 149.

, which form coral reefs, iii/276.

Zuyder Zee, formation of, ii. 5.

THE END

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